Empiricism

Empiricism holds that everything we know about the world we learned from experience. Locke's image is the mind as blank paper: no innate content, only what the senses write on it.^[1] A claim about the world is a posteriori — it answers to observation — and one that doesn't answer to observation isn't telling you about the world at all.

Taken strictly, it bites. Hume followed it to the problem of induction: no amount of past regularity entails that the future will resemble the past, and any argument that it will has to assume the very principle it's defending. Since inductive reasoning is what science runs on, this is not a minor footnote — it is a live problem that empiricism inherits by being honest about its own resources. Hume applied the same knife to causation: we observe one event following another, never the necessity connecting them.

What survives is less a doctrine than a discipline: prefer claims that observation could embarrass. Its opposite number, rationalism, is not the view that observation is useless but that it cannot be the whole story — a debate Kant tried to end by giving each side half.