Occam's Razor and Applications from Medicine to Penal Systems

Occam’s razor (also known as the “law of parsimony”) is a problem-solving principle which serves as a useful mental model. A philosophical razor is a tool used to eliminate improbable options in a given situation. Occam’s is the best-known example.
Occam’s razor can be summarized as follows:
Among competing hypotheses, the one with the fewest assumptions should be selected...

“Everything should be made as simple as possible, but not simpler.” as Einstein famously said.

Of course all of this, as well as use of mental models in general, is a whole lot harder than talking about it.