# Justification versus mental causation

A justification: "we know A is true because B is true."

A mental causation: "I concluded A because first I believed B and that led me to A."

There is certainly a strong relationship between justifications, and stories of mental causation.

They are not the same. A person may think A as a result of thinking B, even though it is not valid or reasonable to do so.

We may think of a justification as a story of mental causation that we approve of. If we agree that a person who thinks B should conclude A, then we would say that B is a valid justification for A. We would say, equivalently, they are justified in concluding A. To say an inference is justified is to say we approve of it.

This is the case even if the inference is not formally valid. A witness in a trial says, "I saw the criminal's face and he looked just like the defendant, so I conclude they are the same person." That's not a formally valid deduction - there are all sorts of ways two people could look the same without being the same. But we might consider it a reasonable justification. And by this we mean that we approve of it.

We may say that a particular way of allowing one thought to cause another is a "method of thought." What does this approval of methods of thought entail? Not necessarily an exhaustive list, but:

• We approve of methods of thought that, when the same rules are applied to practical pursuits, result in the achievement of practical goals. A carpenter uses trigonometry to measure wood to help build a house, giving a practical, useful result. So, we approve of the trigonometry and of the methods of mathematical thought that support it.
• We approve of methods of thought that we already use
• We approve of methods of thought used by those we recognize as experts in a domain
• We approve of methods of thought that do not lead themselves to contradictions.
• We approve of methods of thought that can produce full explanations of their subject matter
• We approve of methods of thought that are simpler to remember and work with, a la Occam's razor

Where - besides C.S. Peirce - can I see this relationship between justification, and mental causation, discussed?

• Possibly this helps: en.m.wikipedia.org/wiki/Cognitive_architecture . psychology also analyses a variety of thinking fallacies and personality disorders, where the relationship between causation and inference matters, because wrong inference need to be treated using some therapy working on causes. May 30, 2022 at 23:13
• ‘Mental causation’ seems an awkward term to me. Do the elements of a story ‘cause’ later events? Mental activity models causal behaviour, but that doesn’t make it subject to that causality. The Problem of Induction says we can only observe patterns. Necessity of logic is only within models, & their accuracy can only be to a certain confidence. Within the realm of observations, we either have tractable models we can check are appropriate or we must be Bayesians. Experts &traditons can be wrong, or inefficient. We need more than ‘what has been approved of’ May 31, 2022 at 16:36
• @CriglCragl I take the position that the mind is a system like any other, and thoughts cause other thoughts over time. May 31, 2022 at 16:41
• We organise experiences into salience landscapes, & we form those into supervening explanatory layers for given domains with causes in their own terms. Eg, character is a far more tractable predictor of other humans than atomic states. But, character is more like, a consistent bias, than a cause in the physics sense. A narrative is another kind of layer - & telling a neat story after distracts from our inability to predict. We have chains of linked mental activities, but I think causal language there, is misleading & problematic. Causal should relate to predictive power. May 31, 2022 at 23:53
• @CriglCragl I take the position that causation is something inherent in nature, prior to any human description of it. The laws of physics were already here, dictating how one universe state led to another, long before humans. Jun 1, 2022 at 1:31