In philosophy, a razor is a principle or rule of thumb that allows one to eliminate (“shave off”) unlikely explanations for a phenomenon. The most obvious explanation is most often correct.
These are my favourites…
Hanlon’s razor – Never attribute to malice that which is adequately explained by stupidity.
Husband’s razor – Never attribute a slightly rough shave of your ruggedly handsome face to a faulty razor, when it is adequately explained by my using it to keep my leg hairs of winter at bay.