A Philosophical razor is a useful reason to cut short an argument. There are many famous ones. These are my top three:
the simplest explanation is usually the best one
never attribute to malice that which can be adequately explained by stupidity
if something can not be settled by experiment or observation, then it is not worthy of debate
This is also called “Newton’s Flaming Laser Sword” because while a good razor is meant to cut away that which is untrue, this cuts away so much more. Yet at the same time, many other common razors (i.e.: Hitchen’s, Sagan’s, Popper’s) fully fit inside this one.