W/ Jimmy Stephens

The Principle of Sufficient Reason (PSR) asserts that for every fact or state of affairs, there must be a sufficient explanation for why it is the case. This principle underlies much of metaphysical and epistemological inquiry, seeking to ensure that the universe is intelligible. However, there are differing ways to formulate the PSR, particularly regarding whether it should explain a fact in isolation or in relation to alternatives. These two approaches—contrastive and non-contrastive—represent distinct ways of applying the principle.

A non-contrastive PSR focuses on explaining why a fact exists without addressing why other possibilities did not occur. It is satisfied by what might be called a “simple reason,” one that accounts for the existence of the fact itself. For instance, if we ask why a tree stands in a field, the non-contrastive PSR would be satisfied by explaining that the tree grew from a seed under favorable environmental conditions. This explanation does not concern itself with why this particular tree exists rather than another tree, or why a tree exists instead of something else, like a rock or nothing at all. It stops at identifying a sufficient cause for the fact in question without regard to hypothetical alternatives.

In contrast, a contrastive PSR demands more. It requires not only an explanation for the existence of the fact but also for why it exists instead of other possibilities. It seeks a “contrastive reason,” one that differentiates the actual fact from its potential competitors. Returning to the example of the tree, the contrastive PSR would not stop at explaining why the tree exists but would also ask why this oak tree exists rather than a pine tree, or why a tree exists at all rather than a treeless field. The explanation must address why this specific outcome was actualized over alternatives, thereby providing a more detailed and exhaustive account.

This distinction reveals an important nuance in how we frame questions about explanation. The scope of inquiry plays a crucial role in determining what counts as a relevant alternative. If the question is, “Why this oak and not another oak?” the alternatives are limited to similar trees. If the question is, “Why a tree and not a rock?” the alternatives broaden. At its widest scope, the question might become, “Why is there something rather than nothing?” Each level of contrastiveness demands a proportionate level of explanatory depth, with broader questions requiring explanations of far greater scope.

The non-contrastive PSR provides a more straightforward framework, often sufficient for many practical inquiries, as it identifies the immediate cause of a fact. However, the contrastive PSR is indispensable when seeking to understand why a particular possibility became actualized in a world of competing alternatives. By addressing not just “why X?” but “why X rather than Y?,” it offers a richer, more nuanced account of reality.

While the non-contrastive approach is more limited, it is often a natural starting point. The contrastive approach, on the other hand, drives deeper into the nature of explanation itself, pushing us to consider the context and assumptions behind our questions. Together, these formulations of the PSR provide complementary tools for exploring the reasons behind the facts of the world. Whether examining local phenomena or tackling ultimate existential questions, the distinction between non-contrastive and contrastive explanations helps clarify the kinds of answers we seek and the explanatory burdens we must meet.

Why Does This Matter?

The Principle of Sufficient Reason (PSR) matters deeply because it engages fundamental questions about freedom, possibility, and the nature of reality. If everything that exists or occurs must have a sufficient reason, does that mean the universe is “locked” into being exactly as it is, with no genuine alternatives? Or is there room for different possibilities, even if what happens still happens for a reason? This question hinges on the distinction between contrastive and non-contrastive formulations of the PSR.

The non-contrastive PSR (NPSR) asserts that everything requires an explanation, but this explanation does not need to address why one specific outcome occurred instead of others. It suffices to say, for example, that a tree exists in a field because it grew from a seed under certain conditions. This explanation satisfies the demand for intelligibility without addressing why an oak tree exists rather than a pine, or why there is a tree rather than a rock—or even nothing at all. The NPSR leaves room for alternative possibilities: it demands reasons for what is, but not why what is was chosen over what might have been.

In contrast, the contrastive PSR (CPSR) insists that explanations account for why one possibility was actualized over others. It asks not just “Why this tree?” but “Why this tree rather than any other possibility?” Whether the scope of inquiry concerns a tree versus another tree, a tree versus a rock, or something versus nothing, the CPSR demands that every alternative be ruled out by the explanation. This approach suggests a tighter grip on possibility: if one outcome is explained contrastively, it can seem that no other outcome was truly possible.

This distinction becomes particularly significant when applied to God’s creation of the world. If God’s reasoning follows the CPSR, it implies that He created this specific world because all other alternatives were ruled out for good reasons. This leads to necessitarianism: the idea that this world is the only possible world, as no other could meet God’s reasons. Under this view, God’s decision was not a free choice among genuinely open possibilities but the inevitable result of a perfectly rational process.

By contrast, if God’s reasoning follows the NPSR, He might simply have had sufficient reason to create a world without needing to rule out all other possibilities. This allows for divine freedom: God could have created a different world, but He chose this one for reasons that explain His act of creation without implying that it was the only possible choice.

Critics often argue that the CPSR leads to necessitarianism by making all alternatives logically impossible. However, the NPSR does not entirely escape this concern. Any sufficient reason for a fact implies that the fact is entailed by its explanation. For something to be entailed, all alternatives must be excluded—meaning that, in practice, even the NPSR may imply that the world is locked into being exactly as it is. This raises an important observation: all simple (non-contrastive) reasons are incomplete contrastive reasons. They rule out alternatives implicitly, even if they do not explicitly engage with them.

Consider the act of creation itself. If God creates possibilities, they must arise from actuality—His act of creation. In this sense, possibility is not independent of God but an extension of His will. This means that even under the NPSR, God’s act of creation effectively determines what is possible. Any explanation of why this world exists must ultimately explain why all other possibilities fail to obtain, collapsing the distinction between contrastive and non-contrastive reasons.

This reasoning has profound theological implications. A purely non-contrastive explanation for creation risks rendering God’s choice arbitrary: if He had no reason to prefer one possibility over another, why create this world? Conversely, a purely contrastive explanation seems to leave no room for genuine alternatives, portraying God as bound by necessity rather than free will.

The resolution may lie in what we might call God’s pure reason—a reason that transcends the simple-versus-contrastive dichotomy. God’s reason for creating the world is not merely simple, as it excludes alternatives and establishes possibility itself. Nor is it strictly contrastive, as it does not rely on preexisting possibilities to motivate His choice. Instead, God’s reason is foundational, generating the very framework of possibility and necessity within which creation unfolds. In this sense, the CPSR and NPSR converge when applied to God, as His act of creation simultaneously explains what is and rules out what is not.

This theological insight reinforces a broader metaphysical point: explanations inherently entail contrastiveness. For any fact to be explained, it must be distinguished from its alternatives, whether implicitly or explicitly. The NPSR’s simplicity is ultimately a subset of the CPSR’s comprehensiveness. Both principles aim at intelligibility, but the contrastive form makes explicit what the non-contrastive form leaves unstated: that every sufficient reason, in ruling something in, necessarily rules something else out.

1. Contrastive PSR

The contrastive version of the PSR says that not only must there be a reason for why something exists or happens, but there also needs to be a reason for why this particular thing happened instead of something else.

For example:

• Why does a particular flower bloom in the spring? A basic reason might be that it’s getting enough sunlight and water. But the contrastive PSR would also ask, why did this flower bloom, instead of a different flower, or why did it bloom this spring rather than in the fall?

If we always need a reason to explain why this specific outcome happened and not something else, then it starts to look like there could only ever be one possible outcome for everything. In other words, if there is always a clear reason for why this world was created instead of some other possible world, or why this particular set of events occurred instead of other possible events, it seems to imply that everything was predetermined—nothing could have been different. This leads to necessitarianism, the idea that the way things are is the only way they could have been.

In short, with the contrastive PSR, everything might seem locked into place by reasons that make only one outcome possible.

2. Non-contrastive PSR

The non-contrastive version of the PSR is a bit simpler. It still says everything needs a reason or explanation, but it doesn’t require an explanation for why one thing happened instead of another. It’s only concerned with the fact that something did happen and has an explanation, without worrying about why this specific outcome happened over other possibilities.

For example:

• Why did the flower bloom? The explanation might be that the flower had the right conditions to bloom. The non-contrastive PSR doesn’t ask why this particular flower bloomed instead of another one or why it bloomed this year instead of last year.

Because this version doesn’t require an explanation for why one specific thing happened rather than another possible outcome, it avoids the problem of making everything seem inevitable. It allows for the possibility that there could have been other outcomes or other worlds, as long as there’s a sufficient reason for the actual outcome that occurred.

In terms of the universe and why things are the way they are, the contrastive PSR seems to suggest that there is a specific reason why this universe exists and not some other possible universe. If you follow this reasoning all the way, it starts to look like there was only one possible universe that could have existed, and that’s the one we live in—because there was a reason to rule out all other possibilities.

On the other hand, the non-contrastive PSR simply says that there’s a reason why some universe exists, but it doesn’t require that we explain why this universe exists instead of another. This leaves room for the idea that other possibilities could have been actualized, avoiding the problem of everything seeming predetermined or inevitable.

Universal Application Without Contingency:

The non-contrastive PSR implies that every fact must have a sufficient explanation, but it does not require that explanation to specify why one possibility occurred over another. This lack of engagement with alternatives leads to the assumption that the event was inevitable simply because a sufficient reason exists for its occurrence. By not addressing alternative possibilities, non-contrastive PSR risks treating the actual event as necessary, since no other outcomes are considered or explained.

This framework implies that, since the event did happen, it was the only possible outcome—a view that aligns with necessitarianism, despite non-contrastive PSR being designed to avoid this very problem.

Non-contrastive PSR implicitly suggests that the actual event was the only possible one because the sufficient cause led to that outcome. Without contrastive reasoning to explore why this outcome occurred instead of others, it implies that no alternatives were ever genuinely possible. This leads to a necessitarian framework, where every fact appears to unfold with absolute necessity—a deterministic view that the non-contrastive PSR purports to avoid.

Example:

Consider an explanation for why a person made a particular decision. A non-contrastive PSR might explain the decision by attributing it to the individual’s upbringing, claiming that this was the sufficient reason. However, this explanation fails to address why the individual’s upbringing led to this specific decision rather than other possible choices. By ignoring these alternatives, non-contrastive PSR implies that the actual decision was inevitable given the sufficient cause, collapsing into necessitarianism.

Responses to Non-Contrastive Necessitarianism

While defenders of non-contrastive PSR might argue that sufficient causes do not necessarily imply necessity, without contrastive reasoning, the explanation remains incomplete. Here’s why:

• Sufficient Causes vs. Necessity: Some might argue that just because a cause is sufficient doesn’t mean it excludes other possibilities. However, without contrastive reasoning, we have no way to evaluate whether those alternatives were genuinely possible, leaving us with the illusion of necessity.
• Implicit Contingency: Another response is that contingency might be implicitly assumed in non-contrastive explanations. But if the alternatives aren’t explicitly explored, non-contrastive PSR leaves us with an arbitrary, incomplete explanation that only reinforces the appearance of necessity.
• Pragmatic Value: Proponents may defend non-contrastive PSR as a pragmatic tool, arguing that it provides a sufficient explanation without needing to explore alternatives. However, PSR’s purpose is to provide a complete explanation for every fact. Failing to account for alternative possibilities leaves explanations underdetermined.

Creator-Creature Distinction: Why the PSR Cannot Be Applied to God

The Principle of Sufficient Reason (PSR) is a valuable tool for explaining contingent, finite realities within creation. It operates within the framework of the created world, where events, entities, and states of affairs rely on external causes for their existence. The PSR helps explain why something is the case rather than otherwise, but when we try to extend this principle to God, we run into significant theological and philosophical problems. God, as the uncaused, self-sufficient, and necessary being, does not require a sufficient reason external to Himself. Applying the PSR to God mistakenly imposes creaturely categories on the Creator, which fundamentally misunderstands God’s transcendence and His relationship to the created order.

God’s aseity—His self-existence—means that He is not contingent in any sense. Unlike contingent beings, which require an external cause or reason for their existence, God’s existence is necessary and self-explanatory. God does not need an external reason for His being; He is the source of all existence, but His own existence does not depend on anything. By contrast, contingent beings—everything within creation—exist only because they have been caused or brought into being by something external to themselves.

This distinction between necessary being and contingent beings is essential. Contingent beings are subject to the PSR because their existence is not self-explanatory—they could have not existed or could have existed differently. But God, being necessary, is not within the realm of contingency. He is existence itself, but not in a way that can be understood univocally with how creation exists. The being of God is radically different from the being of creation.

In this view, even when we speak of God analogically, we must understand that analogical predicates—words and concepts we use to describe God—are created reflections of the way God is, but they do not have univocal content. When we say that God is existence, we do not mean it in the same sense that we might say a creature exists. The term “existence” in relation to God is not univocal; it reflects a truth about God, but only as a creaturely reflection of the incomprehensible reality of God’s existence.

God’s existence is unique—it is not simply an amplified version of the way creatures exist. Instead, God’s being is the source and ground of all created existence, but His being is entirely beyond the framework of modalities and causes that govern created beings. God’s existence is therefore analogical in our understanding but transcendent in reality. The analogies we use to describe God are helpful, but they remain limited and creaturely in their scope, reflecting but not identifying God’s true nature.

Suppose someone asks, “What is the sufficient reason for God’s existence?” This question assumes that God, like contingent beings, requires an explanation external to Himself, which is a category mistake. God, as necessary being, does not require a cause or explanation outside of Himself. His existence is self-sufficient and necessary, while contingent beings depend on causes. To impose the PSR on God is to confuse God with creation, treating Him as a contingent being that requires an external cause or reason, which fundamentally misunderstands the Creator-Creature distinction.

Theological Implications of Misapplying the PSR to God

When we apply human explanatory categories like the PSR to God, we risk reducing Him to a contingent being, dependent on something external for His existence. This contradicts the classical theological understanding of God as the necessary being who is the ground of all existence. God’s existence is self-sufficient, and His aseity means that He requires nothing for His being. If God needed a sufficient reason for His existence, this would imply that God is subject to a higher principle or cause, which would then be the true source of all being. This is theologically untenable because it violates the foundational Christian belief that God is the ultimate reality, beyond which there is nothing.

Unlike finite beings, God is not subject to the modal categories of possibility, necessity, or contingency. These categories are created constructs that apply to the finite world, but God exists outside and independent of them. While we describe the world in terms of what could happen, what must happen, or what might not happen, God’s existence simply is. He is pure actuality, meaning there is no potentiality or possibility in God; He just is. In this sense, even modality itself—the very framework of possibility and necessity—is part of the created order.

God does not fit into modality or the causal framework of the created world because He created them. God’s existence is radically distinct from any created existence, and He does not share properties with creation in any univocal sense. Modality, like causality, is a reflection of how the created world operates, but God transcends these categories entirely. While we, as creatures, think in terms of potential and necessity, God’s existence is beyond those categories—His being is simple, indivisible, and self-sufficient.

When we try to apply the PSR to God, we make a fundamental category mistake. The PSR can be used to explain finite and contingent things, but God is neither finite nor contingent. He is the Creator of all things, not subject to the same principles that govern creation. When we attempt to subject God’s existence to the PSR, we are mistaking God’s nature as something that fits within the created order of causality and modality. This is a critical misunderstanding because God’s existence is not just a greater or infinite version of created existence, but a completely different kind of being.

The Creator-Creature Distinction as the Boundary of the PSR

The PSR is a valuable principle for explaining the contingent world, but it cannot be extended to God without violating the creator-creature distinction. God’s existence is self-sufficient, and He does not require a sufficient reason external to Himself. To apply the PSR to God would collapse His transcendence into the realm of contingency, confusing God’s necessary existence with the contingent existence of created beings. The creator-creature distinction helps us maintain a proper understanding of God’s transcendence, ensuring that our philosophical and theological categories do not blur the line between God and His creation.

By recognizing that even our analogical predicates are created reflections of God’s nature, we safeguard the distinction between God’s being and created being. God’s existence is not a mere extension of creaturely existence, but something radically distinct. This creator-creature distinction preserves the transcendence of God and ensures that we do not impose creaturely principles onto the divine.

Determinism vs. Necessitarianism: Preserving Divine Freedom

One frequent criticism of contrastive PSR is that it may lead to necessitarianism—the view that every event happens out of necessity, thereby leaving no room for genuine contingency. The concern arises from the idea that if every event has a sufficient reason for happening instead of something else, only one possible outcome could ever occur. This seems to deny any true possibility for alternative events.

However, this criticism misunderstands both the nature of contrastive reasoning and the distinction between determinism and necessitarianism regarding God’s act of creation. While determinism—the idea that events follow definite causes—can be consistent with contrastive PSR, necessitarianism falsely claims that God must create the world. Instead, contrastive PSR preserves contingency by explaining how God’s choice to create this specific world was contingent, not necessary.

The distinction between determinism (which operates within creation) and necessitarianism (which would claim that God must create the world) is crucial for understanding divine freedom. The contrastive PSR allows for a world where events unfold according to determined causes, but this doesn’t imply that God’s act of creation itself was necessary. God’s decision to create was entirely free. However, if God chose to create, He would have created this specific world because it uniquely reflects His nature.

In this sense, determinism within the created world reflects God’s specific choice of this world but does not imply that God had to create at all. The necessity here is conditional on God’s choice to create, which was itself a free act, preserving divine freedom while maintaining the necessity of this world once creation was chosen.

Avoiding Necessitarianism While Upholding Determinism

Determinism explains how events unfold according to God’s sovereign will within creation, but it does not imply that creation was necessary. God’s freedom remains intact because creation was a free act, not compelled by necessity. However, once God chose to create, this particular world—one that fully reflects His immutable nature—was the result.

This preserves contingency at the divine level. God did not have to create, yet, when He chose to create, this specific world was necessarily chosen. This prevents necessitarianism because God’s decision to create was free, but the specific world that came into being reflects God’s nature perfectly.

Contrastive PSR avoids necessitarianism by showing that while certain outcomes are determined within the created order, the choice to create in the first place was contingent. The principle explains why specific outcomes occurred instead of others within the world but does not imply that God’s choice to create was necessitated.

Contrastive PSR preserves contingency by explaining how God’s choice to create this world was based on His nature but was not necessary. The existence of this world reflects God’s nature, but the act of creation itself was not compulsory. If God chose to create, this world reflects Him most fully, but creation was not forced upon God.

Both modality (the framework of possibility, necessity, and contingency) and the PSR are created principles. They operate within creation and do not constrain God, who stands beyond these categories. Any necessity we observe within creation reflects God’s sovereign decision, not a limitation on His freedom. Therefore, modality and the PSR apply within the created world, not to God’s free act of creation.

Consider the case of a volcano eruption. If we ask, “Why did a volcano erupt at this specific time?” Contrastive PSR would explain the specific conditions (e.g., tectonic shifts) that led to the eruption at this time rather than earlier or later. This does not imply that the eruption was necessary in an absolute sense; it simply explains why it happened given the specific conditions.

Similarly, God’s choice to create was not forced by necessity. The world He created fully reflects His character, but the act of creation itself was free. The fact that this world reflects God’s nature does not mean that God had to create it; it explains why this particular world was chosen once God freely chose to create.

In Christian theology, moral truths are seen as necessary reflections of God’s immutable nature. These truths, such as “God is love” or “It is wrong to lie,” are not arbitrary but flow necessarily from God’s character. God could not command something like murder to be good, as this would contradict His unchanging nature.

Similarly, if God freely chose to create, the world He created must necessarily reflect His nature. Since God’s nature is immutable, the specific events and order in creation must reflect God’s attributes—such as wisdom, goodness, and justice. A different world would tell a different story about God, which would imply a change in God’s nature, contradicting His immutability.

Objection and Inconsistency

If someone objects to the idea that this world is the necessary result of God’s choice to create, they would face a similar problem with moral truths. Both ideas—moral truths and creation—are grounded in the principle that God’s actions must reflect His immutable nature. To deny that this world was the necessary outcome of God’s creative choice would imply that God’s moral truths could also be arbitrary, undermining the foundation of moral realism in Christian theology.

Conclusion: Consistency in Reflection of God’s Nature

Any objection to the necessity of this world, given God’s choice to create, would undermine other Christian doctrines that rely on the necessity of reflecting God’s immutable nature, such as the immutability of moral truths. Both creation and moral truths are non-arbitrary expressions of God’s character, and challenging one aspect calls into question the coherence of the other.

An essential point is that modality and the PSR are created realities. These principles govern the unfolding of events within the created order, but they do not constrain God. Since God created modality itself, He is not subject to its constraints. God’s freedom remains intact because He stands beyond the categories of possibility, necessity, and contingency that apply to created beings. Therefore, God’s decision to create this world, though it reflects His nature, does not imply that He was constrained by the PSR or modality.

Conclusion: Contrastive PSR and Divine Freedom

In conclusion, contrastive PSR provides a coherent explanation for events in creation while preserving divine freedom and avoiding necessitarianism. It affirms that God’s act of creation was free, not necessitated, while recognizing that once God chose to create, the specific world that came into being necessarily reflects His nature. Determinism describes how events unfold according to causes within creation, but it does not constrain God’s freedom in choosing whether to create.

By recognizing that both the PSR and modality are part of the created order, we can avoid imposing these constraints on God. This framework affirms divine freedom, the necessity of the created world once chosen, and the contingency of creation itself.

God’s decision to create was fully free. He did not need to create, and His existence is self-sufficient. The PSR applies to contingent realities, not to God’s decision to create. This ensures that God’s freedom is preserved—creation was not required for God to be God. Had He chosen not to create, His nature would remain unchanged.

However, if God chose to create, then this specific world is the only possible world that could exist because it reflects God’s immutable nature. God’s attributes—such as goodness, wisdom, and justice—are necessarily mirrored in the created world. Creating a different world would imply reflecting God differently than He truly is, which is metaphysically impossible.

Therefore, while God’s decision to create was contingent, the world He created is the necessary result of His nature. A different world would result in a distortion of God’s character, which cannot happen.

Contrastive PSR explains why this world exists instead of other possible worlds. Once God chose to create, this specific world was the only one that could accurately reflect His unchanging nature. In this way, contrastive PSR preserves both God’s freedom and the necessity of the world once God chose to create.

This view avoids necessitarianism by affirming that creation was not necessary. God did not have to create, but once He did, only this world could exist to reflect His nature fully. This preserves the contingency of God’s choice and the necessity of the created world within the framework of God’s nature.

Conclusion: A World That Reflects God

In summary, God’s freedom is maintained, and necessitarianism is avoided. Once God freely chose to create, this specific world was necessarily the only option that could reflect His immutable nature. Determinism within the created world aligns with contrastive PSR to provide coherent explanations, all while preserving the distinction between God’s freedom and the deterministic nature of the created world.

Non-Contrastive PSR and Underdetermination

A non-contrastive PSR may allow explanations that are too weak or arbitrary. For instance, if we say that X happened due to a sufficient reason but do not explain why X occurred instead of Y (where Y is a possible alternative), the explanation risks being incomplete. It leaves open the question of why one particular state of affairs arose instead of another possible state.

Example:

Imagine someone asks, “Why did it rain today?” and the explanation is simply, “Because the atmospheric conditions allowed for it.” This is a sufficient reason under a non-contrastive PSR. However, it does not explain why it rained instead of remaining sunny or cloudy (other possible outcomes). Contrastive PSR, on the other hand, would demand an explanation for why rain occurred instead of those alternatives, such as “The cold front moved in, causing condensation, which led to rain instead of sunshine.”

This arbitrariness undermines the PSR’s goal of providing a full explanation. Without contrastive reasons to distinguish why X occurred rather than Y, the explanation can seem underdetermined. Multiple, equally valid explanations might exist for a single event, but with no way to choose between them, the principle loses its explanatory power.

Example of Underdetermination:

Imagine two explanations for why a person developed a particular disease: one explanation cites genetic factors, while the other cites environmental exposure. A non-contrastive PSR could accept both as sufficient reasons without requiring a distinction between them. However, without a contrastive reason explaining why this particular person developed the disease due to genetics rather than environmental exposure, or vice versa, the explanation becomes incomplete, leading to underdetermination.

Why Underdetermination is an Epistemic Issue:

Underdetermination presents a significant epistemic challenge because it blocks our ability to determine whether any given explanation is truly justified over its alternatives. In a world governed by underdetermination, we encounter multiple possible explanations for a single event or state of affairs, but none of these explanations has a clear intrinsic advantage over the others. Without the ability to rule out alternative possibilities, we find ourselves in a state of epistemic paralysis, unable to confidently accept any explanation as the truth.

For example, if two explanations for an event—such as genetics and environment being potential causes of a disease—both seem equally valid under a non-contrastive PSR, we cannot determine which one is the true cause. This leaves us with an incomplete understanding of the event because the non-contrastive PSR doesn’t provide a reason for why one possibility materialized over another. Consequently, both explanations remain equally plausible, with no justification for preferring one over the other.

This lack of decisive reasoning leads to a breakdown in our ability to form reliable beliefs. At its core, epistemology aims to provide justified true beliefs, backed by sound reasoning and evidence. When underdetermination prevails, this goal is severely undermined. If we cannot explain why event X occurred instead of event Y, any belief about why X happened is necessarily arbitrary, leading to a fundamental weakening of our knowledge claims.

The Consequences of Underdetermination for Knowledge

The inability to decide which explanation is correct results in a loss of confidence in our knowledge. Without the means to determine true causes, we cannot form reliable beliefs about the world—beliefs that are not only true but also backed by sufficient justification. If we cannot distinguish between equally plausible but competing explanations, our understanding of the world becomes unreliable. This means that any explanation we hold could easily be overthrown by an alternative that is just as plausible, leading to a fundamental uncertainty about what is actually true.

This uncertainty extends across all fields of inquiry, from science to philosophy to everyday reasoning. In scientific inquiry, for example, we rely on empirical evidence to guide us toward the true causes of phenomena. But in a world governed by underdetermination, evidence alone is often insufficient to resolve competing theories. As a result, even scientific theories, which are typically seen as the best explanations for natural phenomena, could be equally valid alongside other, completely different theories. Without contrastive reasoning to rule out alternatives, science itself loses much of its explanatory power.

Underdetermination and Skepticism: The Broader Implications

Underdetermination leads to a broader philosophical issue: skepticism. Skepticism is the view that certain knowledge is impossible, and underdetermination is a key factor in fostering this view. If we cannot definitively resolve which explanation is correct, we cannot claim to know anything with certainty. This leads to a skeptical stance about all of our beliefs, whether in the context of science, ethics, metaphysics, or everyday experiences.

For instance, if we have two equally plausible but contradictory explanations for an event, and no way to determine which one is correct, then any belief we form about the event is subject to doubt. We might prefer one explanation over another, but we must always acknowledge that the alternative explanation could just as easily be true. This type of epistemic doubt extends beyond individual cases to the very structure of our knowledge, creating pervasive uncertainty about the reliability of our beliefs.

In short, underdetermination introduces systemic doubt into our belief system. It leaves us unable to know for certain why things happen as they do or whether our understanding of the world accurately reflects reality. This loss of epistemic confidence is a major consequence of underdetermination, making it a critical issue for any epistemic framework that seeks to provide justified, reliable knowledge.

The Humean Skeptical Threat: Non-Contrastive PSR and Habitual Observation

The problem of underdetermination becomes even more significant when viewed through the lens of Humean skepticism. David Hume famously argued that our belief in cause-and-effect relationships is not based on reason or necessity, but rather on habit. When we observe two events happening together—for example, a rock hitting a window and the window shattering—we come to expect that the rock’s impact causes the window to break. However, Hume pointed out that we do not actually observe the necessary connection between these two events. All we observe is that they are constantly conjoined.

Hume’s critique directly applies to the non-contrastive PSR, which assumes that sufficient causes explain why events occur. Non-contrastive reasoning asserts that “X happened because Y was its sufficient cause.” But, as Hume would argue, this reasoning assumes a necessary connection between the events without ever observing that necessity. The non-contrastive PSR merely states that X occurred because of Y, without ruling out other possible causes or explaining why this particular outcome occurred rather than some alternative.

Without contrastive reasoning to justify why one event happened instead of another, we are left with explanations based on habitual observation rather than any deeper understanding of causal necessity. This skepticism aligns with Hume’s point that our explanations are often based on patterns of expectation rather than any intrinsic causal connection. In such a framework, cause and effect are reduced to mere conjunctions—the expectation that, because two things have occurred together in the past, they will continue to do so in the future.

This view represents a significant epistemic loss, as it strips our explanations of any claim to necessity or deeper insight. We are left with a shallow, superficial grasp of reality, where we no longer understand why things happen, only that they tend to happen together.

The Impact on Predictive Power and Knowledge

The inability to determine true causes and the collapse into habitual observation have devastating consequences for our ability to predict future events. Science, philosophy, and everyday reasoning all rely on the assumption that by understanding the causes of events, we can predict their effects. If, however, we cannot determine why certain events occur rather than others, our predictive power becomes unreliable.

For example, in medical science, if two different explanations (genetics or environmental factors) are equally valid for why a person developed a disease, and we have no contrastive reasoning to prefer one over the other, our ability to predict who might develop the disease in the future becomes severely compromised. With no basis for expecting one outcome over another, our predictions become unreliable, and our understanding of the phenomena becomes weakened.

The Devastating Consequences of Underdetermination and Humean Skepticism

In conclusion, underdetermination—when combined with Humean skepticism—presents a serious threat to our ability to understand and know the world. Without contrastive reasoning, explanations become arbitrary, unjustified, and underdetermined, leaving us with no reliable way to discern true causes from false ones. In a world where explanations are based on habitual observation rather than necessary connections, we lose the ability to understand why events occur and how they relate to one another.

This represents a significant epistemic loss, reducing our grasp of the world to mere conjunctions—events that happen to coincide, without any deeper insight into why they do so. The consequences of this loss are far-reaching: skepticism undermines our confidence in knowledge, scientific inquiry loses its explanatory and predictive power, and our ability to navigate the world based on reason and evidence is severely compromised.

Reflexive Application of PSR: The Problem of Explaining the PSR Itself

One of the most significant challenges with the Principle of Sufficient Reason (PSR) is the reflexive problem: how do we apply the PSR to itself? If the PSR demands that every fact must have a sufficient explanation, it must also explain why it, as a principle, is true rather than not true. This introduces a dilemma regarding whether we use a non-contrastive or contrastive approach to explain the PSR.

Non-Contrastive PSR Applied to Itself

In this scenario, the non-contrastive PSR would provide an explanation for why the PSR holds, but it would not explain why the PSR holds rather than an alternative principle. This leads to a form of arbitrariness, because it fails to answer the key question: why is the PSR the valid principle rather than some other framework (such as a principle that suggests not all facts require explanation, or even no principle at all)?

Example of Non-Contrastive Reflexivity

Suppose we ask, “Why is the PSR valid?” A non-contrastive PSR response might say, “Because we observe the need for explanations in the world.” However, this explanation doesn’t address why this principle holds instead of an alternative like “Some facts have no sufficient reason.” The failure to address this leaves the justification for the PSR incomplete and potentially arbitrary.

Contrastive PSR and the Issue of Applicability

If we apply a contrastive PSR to itself, we must explain why the PSR holds instead of some alternative principle. While this might seem to provide a better justification, it raises a larger question: When and why is contrastive reasoning necessary?

If the PSR is justified through a contrastive reason, why should contrastive reasoning apply only in certain cases (such as justifying the PSR itself) and not universally across all facts? This selective use of contrastive reasoning introduces inconsistencies and arbitrariness in the application of the PSR.

The Meta-Problem: A Higher Principle

If contrastive reasoning is required to justify the PSR, this implies there must be a meta-principle that governs when contrastive reasoning applies. This meta-principle would explain why contrastive reasons are needed for some facts but not others. However, this leads to several new challenges:

• Regress: If a higher principle is required to explain when contrastive reasoning applies, does this principle itself require a contrastive reason? If so, we enter into an infinite regress, where each principle requires yet another level of explanation, ultimately undermining the PSR’s goal of providing clear, sufficient reasons.
• Arbitrariness: If no meta-principle is offered or if it is not subject to contrastive reasoning, we risk making arbitrary distinctions about when contrastive reasoning is used. Why apply contrastive reasoning to the PSR and not to other facts? This lack of consistency weakens the PSR’s role as a universal explanatory principle.

Undermining the Universality of the PSR

By limiting contrastive reasoning to select cases, the universality of the PSR is compromised. Traditionally, the PSR is understood as applying to all facts and events, demanding a sufficient explanation for everything. However, if we only apply contrastive reasoning in specific instances (such as justifying the PSR), this undermines the scope and consistency of the PSR.

Inconsistent Application

The selective application of contrastive reasoning creates an inconsistent framework. If contrastive reasoning is used to justify the PSR but not in other cases, this calls into question the reliability and universality of the PSR. Why does the PSR require a contrastive reason while other facts or principles do not? Such selective use of reasoning threatens the PSR’s integrity as a universal explanation for all facts.

Undermining the Scope of the PSR

The strength of the PSR lies in its scope—it provides explanations for all facts and events. However, if contrastive reasoning is only used in certain cases, the PSR’s scope is limited. This leads to an unstable framework where some facts are explained contrastively, others non-contrastively, and some not at all. Such fragmented application challenges the foundational purpose of the PSR as a consistent and comprehensive explanatory principle.

The Reflexive Issue Revisited

Grounding the PSR in contrastive reasoning brings the reflexive issue back in a different form. If the PSR is justified by a contrastive reason, we still need a principle that explains why the PSR itself should be explained contrastively. But this introduces the same problems of circularity or infinite regress.

• Circularity: The explanation for the PSR could end up relying on itself, creating a circular argument where the PSR is justified by a contrastive explanation that assumes the PSR’s validity in the first place.
• Regress: If each contrastive explanation requires further justification, we face an infinite regress where no single explanation is sufficient on its own. This undermines the very purpose of the PSR, which is to provide a complete and sufficient reason for each fact or principle.

Conclusion: The Problem of Selective Contrastive Application

The core issue with using contrastive reasoning to ground the PSR is that it introduces inconsistency and arbitrariness. If we apply contrastive reasoning to the PSR, we must explain why contrastive reasoning is used in this instance but not universally. This opens the door to regress, inconsistent application, and the need for a higher principle to justify the selective use of contrastive reasoning. Ultimately, this undermines the universality, consistency, and explanatory power of the PSR.

By selectively applying contrastive reasoning, we weaken the PSR’s ability to serve as a universal explanatory principle, leading to incomplete explanations, circular reasoning, and arbitrary distinctions. Thus, the reflexive application of the PSR remains a challenge that undermines its universality and coherence as a comprehensive principle for explaining all facts and events.res a sufficient reason?” the explanation must distinguish why the PSR is superior. If the response is that “The PSR provides a better foundation for understanding reality,” then we would need another explanation for why the PSR is better—leading to a potential infinite regress of justifications, undermining the PSR’s simplicity.

The Role of Intention in Moral Responsibility: A Necessary but Insufficient Condition

The tension between intention and action in moral reasoning becomes even more pronounced when viewed through the lens of the non-contrastive Principle of Sufficient Reason (PSR). If we accept a non-contrastive PSR, where there is no sufficient reason to explain why certain actions follow from specific intentions, then moral absurdities begin to emerge. The disconnect between intention and action undermines moral responsibility and, more significantly, contradicts the biblical teaching that emphasizes both the importance of intentions and the necessity of their connection to actions.

1. The Non-Contrastive PSR and Moral Absurdity

A non-contrastive PSR posits that while there may be a reason for why an action occurs, it does not explain why this particular action occurred rather than another possible action. Applied to the moral realm, this principle suggests that intentions are irrelevant in determining why a particular action happens. This means that even if someone has good intentions, the specific actions that follow are arbitrary or unrelated to those intentions.

For example, if someone intends to help a friend, but their action inadvertently harms the friend, a non-contrastive PSR would not require a reason why that harmful action followed from the good intention. This leads to the moral absurdity that actions can be disconnected from intentions, leaving no basis for moral accountability.

2. Intention as a Necessary Condition in the Bible

Biblically, intentions are essential to moral responsibility. Scripture consistently teaches that God judges both the heart (intentions) and actions, and that moral judgment is not based on actions alone. Verses like 1 Samuel 16:7 (“The Lord looks at the heart”) and Proverbs 16:2 (“All a person’s ways seem pure to them, but motives are weighed by the Lord”) emphasize that God values intentions as a crucial component of moral judgment. Jesus also affirms this connection by condemning not just outward actions like murder or adultery, but the inner attitudes of anger and lust that lead to those actions (Matthew 5:21-22, 27-28).

However, the non-contrastive PSR weakens the moral importance of intentions, suggesting that actions can occur without any clear connection to those intentions. This is deeply unbiblical because it violates the scriptural teaching that moral actions must reflect the intent of the heart. If actions can be arbitrary or disconnected from intentions, then the moral weight of intentions becomes irrelevant.

3. Good Intentions Do Not Guarantee Good Outcomes

Even if we accept that good intentions are necessary, they are not sufficient for ensuring morally good outcomes. If the PSR does not provide a sufficient reason linking intentions to the correct actions, moral disconnection occurs. Under a non-contrastive PSR, it becomes possible to have good intentions but choose actions that are harmful or morally wrong, and yet there is no requirement to explain why that specific harmful action occurred instead of a good one.

Consider the biblical example from Romans 10:2-3, where Paul addresses the Israelites’ zeal for God: “For I can testify about them that they are zealous for God, but their zeal is not based on knowledge.” Despite their good intentions, their actions were misguided and ultimately led them away from God’s righteousness. In this case, the disconnection between intention and proper action demonstrates the moral danger of ignoring the relationship between what one intends and what one does.

The non-contrastive PSR allows for a situation where a person can claim good intentions but perform morally harmful actions without sufficient reason to link the two. This moral disconnection not only weakens personal responsibility but also challenges the biblical understanding of moral integrity, where actions must reflect the purity of one’s heart.

4. Undermining Moral Responsibility

If intentions are disconnected from the actions they produce, as suggested by the non-contrastive PSR, moral responsibility is fundamentally undermined. A person can claim that their intentions were good, but without a reason linking those intentions to a morally appropriate action, they can absolve themselves of responsibility for any negative consequences. This creates a moral loophole where individuals are no longer accountable for the outcomes of their actions because their good intentions supposedly suffice.

In Matthew 7:21-23, Jesus directly addresses this issue: “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven.” Even though individuals may intend to serve God, their actions must align with God’s will. The non-contrastive PSR would create a scenario where individuals could claim they had good intentions without being held responsible for their morally ineffective or harmful actions, an idea that runs counter to this biblical teaching.

5. Moral Confusion and Lack of Guidance

A non-contrastive PSR also leads to moral confusion by failing to offer clear guidance on how to align intentions with correct actions. If there is no sufficient reason explaining why one action follows from an intention rather than another, then moral agents are left in a state of ambiguity. Ethical decision-making requires that actions fulfill intentions, but without contrastive reasoning, individuals have no way to ensure that their actions will achieve their intended moral goals.

The Bible warns against this kind of confusion. James 1:5 instructs believers to seek wisdom, stating, “If any of you lacks wisdom, you should ask God, who gives generously to all without finding fault, and it will be given to you.” Wisdom involves not only having good intentions but also knowing how to act in alignment with those intentions. Without a sufficient reason to link intentions with proper actions, moral confusion ensues, leaving individuals unsure of how to act righteously.

6. Ethical Arbitrariness

When the non-contrastive PSR fails to provide a sufficient reason connecting intentions to actions, it opens the door to ethical arbitrariness. A person may intend to do good but end up performing actions that are morally irrelevant or even harmful. Without contrastive reasoning to justify why a particular action should follow from a good intention, moral agents may choose actions arbitrarily, leading to outcomes that contradict their intentions.

For example, someone who intends to help the poor may donate to a charity that is ineffective or even corrupt. Without contrastive reasoning to explain why one action (donating to a certain charity) is better than another (choosing a more effective organization), the individual’s action may be morally disconnected from their intention, resulting in ethical failure.

7. Undermining Biblical Moral Responsibility

This disconnection is not only a philosophical problem but also a theological one. The Bible teaches that both intentions and actions are essential in moral evaluation. The disconnect created by the non-contrastive PSR runs contrary to the biblical principle that right actions must flow from right intentions. In passages like James 2:14-17, where faith is dead without works, and Matthew 7:16-20, where a tree is judged by its fruit, the Bible makes clear that both intentions and actions matter.

A system that fails to sufficiently link intentions to actions undermines the Bible’s moral framework. Without this connection, moral agents may act in ways that are not aligned with their intentions, leading to moral confusion, ethical arbitrariness, and a breakdown in moral responsibility.

8. Secular Moral Theories Fail by Neglecting the Importance of Both Act and Intent

Secular ethical theories often fall short because they fail to give proper weight to both intentions and actions in moral reasoning. Some ethical systems, like consequentialism, focus almost exclusively on the outcomes or consequences of actions, while others, like virtue ethics, emphasize character and the cultivation of moral virtues. In both cases, the relationship between intention and action can become underdeveloped, leading to a moral deficiency in these systems.

• Consequentialist theories, for example, argue that the moral worth of an action is entirely dependent on the results it produces. However, this can lead to moral absurdities, where individuals with good intentions are condemned for unfortunate outcomes they couldn’t foresee or control, or where those with selfish or malicious intentions are praised because their actions happened to result in a positive outcome. In this framework, good intentions hold little to no weight, which not only overlooks the moral worth of the individual but also fosters ethical confusion about responsibility.
• On the other hand, deontological systems focus heavily on duty and rule-following, often overlooking the consequences of an action. While these theories better account for the role of intention, they may still fail to properly assess the outcome of an action, leading to a disconnection between moral intent and the real-world effects of one’s actions. This can lead to a situation where someone is morally “correct” in their intent, but the actions they take cause harm, which the theory may inadequately address.

A complete moral framework must take into account both the intentions behind an action and the action itself, ensuring that there is a coherent connection between the two. In failing to do this, secular moral theories often neglect the wholeness of moral responsibility. The Bible, in contrast, provides a robust system where both the heart (intention) and actions are evaluated together, offering a more comprehensive view of human moral agency.

How Non-Contrastive PSR Exposes the Problem in Secular Ethics

The non-contrastive PSR highlights a weakness in secular theories because it allows for moral evaluations that separate the intent from the act, a failure that can result in arbitrary moral assessments. Secular theories often lack a robust mechanism to ensure that a person’s intentions are properly reflected in their actions. Without contrastive reasoning to justify why a particular action should follow from a given intention, secular systems allow for a disconnect that leads to moral inconsistencies, weakening their explanatory power.

For instance, consequentialism fails to address why a good outcome should absolve morally problematic intentions, and deontology might overlook the negative consequences of actions motivated by virtuous intent. Both systems falter because they don’t sufficiently explain why a particular action should follow from a specific moral intention, relying instead on either the results or the rule itself, thus losing a critical part of the moral equation.

Conclusion: By neglecting the link between intention and action, secular theories struggle to provide a full account of moral responsibility. Biblical ethics and contrastive PSR, however, present a more coherent and holistic moral framework where intentions are seen as necessary, but not sufficient, for moral evaluation. Both intentions and actions must align for a moral system to truly function, something secular ethics often fails to account for adequately.

Conclusion: The Moral Crisis of Non-Contrastive PSR

In sum, the non-contrastive PSR creates a significant moral problem by disconnecting intentions from actions. This disconnection leads to moral absurdities where individuals can act in harmful ways despite having good intentions, and yet have no sufficient reason for why their actions do not align with their intentions. This idea is unbiblical because it contradicts the scriptural teaching that both the heart and actions are judged together.

Jimmy’s critique highlights the moral incoherence that arises when the non-contrastive PSR is applied, demonstrating that the disconnection between intention and action weakens personal responsibility, encourages ethical arbitrariness, and conflicts with the consistent moral teaching of Scripture. For moral agency to be meaningful, intentions and actions must be linked by sufficient reasons, preserving both the integrity of personal responsibility and the coherence of biblical moral reasoning.

Conclusion

In summary, the disconnection between intentions and actions under a non-contrastive PSR creates practical problems in moral reasoning. It weakens the link between what we intend to do and the actual moral value of our actions, undermining moral responsibility, ethical guidance, and the integrity of moral theories. Without clear reasons to connect intentions to actions, ethical decisions risk becoming arbitrary, leading to moral confusion and potentially harmful consequences despite good intentions. This is why it is crucial to address the moral gaps left by a non-contrastive PSR and ensure that intentions and actions are meaningfully connected through sufficient reasoning.

Furthermore, the non-contrastive PSR, while offering a simple explanatory framework, collapses under deeper scrutiny due to its inability to fully explain why specific events occur over others. The principle’s failure to account for why one state of affairs happens instead of an alternative introduces severe issues of underdetermination, arbitrariness, and insufficient explanatory power.