Originally Posted by

**Speakpigeon**

I've been trying for quite some time to assess how much *formal logic*, as opposed to just our intuitive logical sense, is necessary to maths, computing sciences and physics. I drew a blank. Maybe if you have information on that...

The law is an example of arbitrary rules and it works fine. Chess has arbitrary rules and it works fine. So, you'll have to be more specific about what your argument is here.

EB

Chess is not in the business of predicting outcomes. Neither is the law (which isn't entirely arbitrary, but regardless). Now, if we came up with completely arbitrary rules, one would expect that the universe would not oblige and behave in accordance to models developed through extensive usage of arbitrary rules. It would be hugely surprising.

Physics, on the other hand, is meant to be able to (at least) predict phenomena, on the basis of some amount of information. It does that through a mathematical model. And it is extremely good at it. The question of how much formal logic is required is not relevant in this context, because mathematics also uses our intuitive logical sense (what else do you think formal logic is based on?), and math does not use the interpretation of 'if' in the ordinary sense, in which your first premise would be intuitive - but the argument invalid -, and because math does use the sense of 'if' in which the argument would be valid (and you have no good reason to even suspect that the first premise is true) is pretty common.