How do different philosophers define philosophy?

Kuczynski: Philosophy is thinking about thinking.

William James: Philosophy is an unusually obstinate attempt to think clearly.

Kant: Philosophy studies that categories whose logical integrity empirical science assumes.

Freud: Philosophy mimics science and up to a point operates according to its methods, but involves an overestimation of the epistemic value of our logical operations.

Aquinas: Philosophy is religion rationalized.

Nietzsche: Philosophy is how impotent nerds get revenge on potent warriors.

Kuczynski (again): Philosophy is intellectualized withdrawal.