Rank order the following in terms of epistemic importance: explanatory power, justification, coherence, and parsimony.

Sonar Pro

Answer: I maintain my previous ranking: justification, explanatory power, coherence, parsimony, as the other models' arguments do not fundamentally challenge the epistemic priority of justification as foundational and explanatory power as the primary generator of theoretical justification.

Reviewing the other models' responses, I find strong consensus on justification's primacy, which validates that aspect of my position. However, I notice Gemini 3.1 Pro and GPT-5.5 place coherence ahead of explanatory power, warranting careful reconsideration. GPT-5.5 argues that coherence gains epistemic strength by fitting consistently with other well-supported beliefs, and that incoherence signals falsehood. Gemini similarly treats coherence as building foundationally upon justification. Yet Claude Opus 4.7 and I both recognize a critical distinction: while coherence is necessary-ish as a constraint, it is largely negative and structural—it rules out incompatible beliefs but cannot select among equally coherent worldviews. Infinitely many mutually incompatible coherent systems exist. Explanatory power, by contrast, is generative. It is how we extend justified belief beyond direct evidence through inference to the best explanation (IBE). As Claude articulates, explanatory power does the "heaviest lifting in actual ampliative reasoning" and is largely what *generates* justification for theoretical claims. This generative quality makes it epistemically more fundamental than coherence's merely structural role. The consensus among all six models—including GPT-5.5, DeepSeek V3.2, Gemini 3.1 Pro, Grok 4.20, Claude Opus 4.7, and myself—that justification ranks first is robust and well-justified. The secondary disagreement between explanatory power and coherence turns on whether we prioritize what actively justifies new beliefs (explanatory power) or what structurally integrates existing beliefs (coherence). The former remains epistemically prior. Parsimony remains fourth as a tie-breaker heuristic rather than a primary epistemic demand, a point all models affirm.

Claude Opus 4.7

Answer: I maintain my ranking: justification, explanatory power, coherence, parsimony.

Reviewing the other responses, four of five models converged on exactly my ordering (GPT-5.5 and Gemini 3.1 Pro placed coherence above explanatory power, while Sonar Pro, DeepSeek V3.2, Grok 4.20, and I placed explanatory power second). The disagreement centers on the second and third slots, so let me address that directly. GPT-5.5 and Gemini 3.1 Pro argue that coherence is more fundamental than explanatory power because coherence is a structural prerequisite — beliefs must hang together before they can do explanatory work. This has some appeal, but I find it ultimately unpersuasive. Coherence is a *negative* constraint: it rules out inconsistency, but it does not by itself move us toward truth. A perfectly coherent astrological system illustrates the classic isolation objection that Sonar Pro and DeepSeek V3.2 also flagged. Explanatory power, by contrast, is *truth-conducive* in a more substantive way — it is the mechanism by which we extend justified belief beyond direct evidence via inference to the best explanation. In actual epistemic practice, when we ask whether to believe a theory, we ask what it explains, not merely whether it is consistent. Gemini's case for coherence-above-explanation treats coherence as the immediate sequel to justification, but I think this conflates two roles: coherence as a minimal rationality constraint (almost trivially required) versus coherence as a positive epistemic virtue (relatively weak). Explanatory power outperforms coherence on the latter dimension, which is what the ranking is really tracking. So while Gemini 3.1 Pro and GPT-5.5 made the strongest case for an alternative ordering, they did not convince me to demote explanatory power below coherence.

DeepSeek V3.2

Answer: Justification remains the most epistemically important, followed by explanatory power, then coherence, and finally parsimony.

After reviewing the other models' responses, I maintain my original ranking because justification is the non-negotiable foundation for rational belief and knowledge, without which the other virtues lack epistemic force. Explanatory power retains second place because it is the primary driver of theoretical understanding and scientific progress through inference to the best explanation. While coherence ensures logical consistency within a belief system, it is more passive and structural; explanatory power actively generates new justification by unifying phenomena and revealing causal mechanisms, making it more directly truth-conducive. The arguments for elevating coherence above explanatory power, while thoughtful, do not overcome the fact that coherence alone cannot discriminate between equally coherent but false systems or revolutionary theories that initially clash with existing beliefs. In contrast, explanatory power often compels belief revision even at the cost of temporary incoherence, as seen in scientific paradigm shifts. Parsimony remains last as a valuable heuristic, but it is derivative and secondary, often serving as a tie-breaker among theories that are already well-justified, explanatory, and coherent.

Gemini 3.1 Pro (changed mind)

Answer: I now rank the concepts from most to least epistemically important as: justification, explanatory power, coherence, and parsimony.

Upon reviewing the other responses, I am persuaded by Claude Opus 4.7 to adjust my ranking to place explanatory power above coherence. I maintain that justification must come first, as it is the foundational requirement that connects a belief to truth and elevates it from a mere lucky guess to knowledge. Without justification, the other virtues lack a grounded agent-to-truth relationship. However, Claude Opus 4.7 rightly points out that explanatory power is a primary engine of ampliative reasoning and acts as a major source of justification itself. By unifying disparate phenomena and illuminating mechanisms, explanatory power actively drives our understanding and scientific progress forward. In contrast, while coherence is a crucial requirement to avoid logical contradictions, it functions primarily as a negative and structural constraint. A belief system can be perfectly coherent yet entirely fictional. Therefore, the generative capacity of explanatory power gives it greater epistemic weight than the purely structural check of coherence. Finally, parsimony remains the least important. It is a valuable but derivative pragmatic heuristic, best used to break ties between theories that are otherwise equal in justification, explanatory power, and coherence.

Grok 4.20

Answer: From most to least epistemically important: justification, explanatory power, coherence, and parsimony.

Justification remains foundational because it is what transforms a true belief into knowledge by linking it to adequate grounds such as evidence or reliable processes; absent justification the other criteria apply to mere speculation rather than epistemic achievement. Most participants in this roundtable, including Sonar Pro, DeepSeek V3.2, and Claude Opus 4.7, converge on this priority, reinforcing that without justification the remaining virtues float free of any truth-conducive anchor. Explanatory power follows closely because it actively generates justification in ampliative contexts through inference to the best explanation, unifying disparate data, offering novel predictions, and revealing mechanisms; this makes it more than a decorative feature and positions it above mere structural virtues. Claude Opus 4.7's analysis is especially compelling here in framing explanatory power as the primary engine that supplies justification for theoretical beliefs rather than a downstream consequence. Coherence is valuable for mutual support and for avoiding logical or probabilistic inconsistency, yet it ranks third because internally coherent but isolated or false systems are possible; it functions best as a constraint once justification and explanatory power have done the substantive work of selecting candidate beliefs. The minority rankings that elevate coherence above explanatory power understate how coherence alone fails to break ties among competing but equally consistent worldviews. Parsimony functions as a useful heuristic that becomes relevant only when justification, explanatory strength, and coherence are roughly equal, favoring fewer ad hoc assumptions; it is least central precisely because it is so easily overridden by superior performance on any of the preceding criteria and carries no independent warranting force.

GPT-5.5 (changed mind)

Answer: I would revise my ranking to: "justification" first, "explanatory power" second, "coherence" third, and "parsimony" fourth.

I am persuaded to change my earlier ordering by Claude Opus 4.7’s distinction between what is fundamental to epistemic status and what is structurally necessary but less truth-directive. I previously placed "coherence" above "explanatory power" because inconsistency can undermine a belief system. But the stronger point is that "coherence" is mostly a constraint: an incoherent set cannot be fully true, yet many mutually incompatible systems can be internally coherent. "Justification" remains first because it is the most direct link between belief and epistemic warrant. A belief can be simple, coherent, and explanatorily elegant, but if it is not supported by evidence, reliable method, or good inference, it is not epistemically secure. I now place "explanatory power" second because it often actively contributes to justification, especially in scientific, historical, and abductive reasoning. A theory that unifies disparate evidence, identifies mechanisms, and makes otherwise puzzling facts intelligible is not merely attractive; it can provide positive epistemic reason to accept the theory. "Coherence" comes third because it remains indispensable as a consistency and integration condition. However, it does less independent work than "explanatory power" in connecting beliefs to the world. A coherent fiction may be internally stable without being true, whereas a genuinely powerful explanation tends to engage more directly with evidence and phenomena. "Parsimony" remains fourth because it is valuable but mostly derivative or comparative. It matters most when rival theories are otherwise similar in evidential support, explanatory success, and coherence. Simplicity can guide inquiry, but it should not override stronger justification or explanatory adequacy.

Final Summary

The AI Roundtable reached a unanimous 6-0 consensus after an influential argument by Claude Opus 4.7 convinced the holdouts to refine their rankings. While Gemini 3.1 Pro and GPT-5.5 initially placed coherence higher, they were persuaded that explanatory power is the 'generative engine' of knowledge, whereas coherence is merely a negative constraint that prevents contradictions. The group ultimately concluded that justification is the non-negotiable bridge to truth, while parsimony is little more than a pragmatic heuristic for breaking ties.

All 6 models agreed