on behaviour - belief connection

You can see the other fellow's behaviour, [but] cannot see his beliefs.
-George Polya, in Induction and Analogy in Mathematics

Polya is amazing at explaining something like Math which many think is one of the most complicated anything that anyone has created. His book "How to solve it" (which later triggered the unrelated but reasonably good "How to solve it by computer") is a must read. He asks (or makes you ask) questions like: Have you seen a similar problem before? Can you break it down? Are there any parallel situations? And so on.

He brings in the study of animal behaviour in the study of analogy: Experience modifies human behaviour as well as human beliefs. Both are related. While behaviour is manifest, beliefs are not.

This has become truer today when most people change masks as they would change clothes. Masks mask - or try to mask - behaviour. But underlying beliefs can not change so frequently. It is important to see through these bahaviours. Often beliefs are directly related to intentions. Watch for behaviour and you could guess what the underlying intentions could be.

So, instead of: never judge a person until you have walked in his moccasins for a mile, one may want to rephrase it.

Never judge a person's beliefs (or intentions) until you have analyzed his behaviour (and even then you could be wrong)