Rules of Philosophizing

In The Principia, Newton developed rules of philosophizing. His fourth rule goes as follows:

"In experimental philosophy, propositions gathered from phenomena by induction should be considered either exactly or very nearly true notwithstanding any contrary hypotheses, until yet other phenomena make such propositions either more exact or liable to exceptions. … This rule should be followed so that arguments based on induction may not nullified by hypotheses.” (p. 796)

What this basically says is that empirically verified theories should not be undermined by a priori, logical possibilities. This effectively removes the bite from many of the skeptical thought experiments that have caused anxiety amongst so many as they worry about proving the independent existence of the external world. (As an aside, the problem of the evil demon has never elicited the necessary intuitions that would cause me to doubt the corrigibility of my senses. This is mainly because I don’t see it as metaphysically possible. Of course, our metaphysics could turn out to be wrong but this again is more of a logical or epistemic possibility. Therefore, epistemic possibility does not immediately undermine an empirically justified metaphysics. Sorry, David Chalmers.)

I think this is generally a good rule to follow especially in the fields of metaphysics and epistemology. It also got me thinking of if there are other rules of philosophizing that we could add to Newton’s. One that I strongly believe in is the prohibition of appealing to speculative hypotheses in math and physics to justify a dubious position. I have in mind countless appeals to either chaos theory in math and quantum mechanics (Copenhagen interpretation) in physics to back up claims of relativism, idealism, the impossibility of knowledge, etc. (I would also include appeals to Gödel’s theorem even though it is better established than the other hypotheses, but I think it is misused in the same way.) Why this is problematic is because not only do those appealing to these theories usually lack the depth of knowledge to effectively use them, but, moreover, they are questionable within their respective fields. Most use them as mysterious black boxes that are supposed to prove whatever absurd or ideologically driven theory they are supporting. Idealism? Quantum mechanics! Indeterminism? Chaos theory! No absolute truths? Gödel’s incompleteness theorem! Fail!

Can anyone think of others you’d like to include?