Heuristics of Formalism
Exhuastion: if a formalism is old, then we probably know everything worth knowing about it.
Sterility: If a formalism needs lots of work to justify simple results, then it's probably the wrong one.
Similarity: If two wildly different formalisms are doing oddly similar things, then there's probably one uniting them.
Contagion: If two formalisms derive from a single one, then they probably do the same things.
Illusion: If a formalism's ideal/abstract entities outweigh its concrete/calculational ones, then it can probably say nothing useful.
Connection: A formalism's value equals the extent to which it can freely interact with other formalisms.
Fluidity: In a good formalism, what you can do, you can also undo.
Diversity: Many theories derive the same theorems. There is no single best explanation.
Novelty: Only essentially new ideas count. Stale thought sickens.
Obscurity: The destructiveness of a formalism equals the number of thoughts it prevents us from thinking.
Humanity: Proving that you can do it, given infinite time and unlimited knowledge, is not the same as proving that you can do it, given little time and paltry knowledge.
Inquiry: Questions teach us more than answers. The purpose of a formalism is to produce better questions.