Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

The Joke

A philosopher presents a rigorous logical argument that leads to an absurd conclusion (like "chairs don't exist" or "you can't actually know anything"). When challenged, the philosopher insists the logic is valid and the conclusion follows necessarily. The other person points out that if your logic leads to the conclusion that chairs don't exist, maybe the problem is with your logic, not with chairs.

The Humor

This is a comic about the tension between logical validity and common-sense realism. In philosophy, there are many technically valid arguments that lead to conclusions most people find absurd (various forms of radical skepticism, mereological nihilism, etc.). The comic sides with common sense over logical cleverness, echoing Dr. Johnson's famous "refutation" of idealism by kicking a stone.

Philosophical Context

The joke references what philosophers call "moorean" arguments (after G.E. Moore): if an argument's conclusion is less plausible than its premises, you should reject a premise rather than accept the conclusion. "I have hands" is more certain than any philosophical argument against the existence of hands.