Philosophical skepticism
（重定向自Antiskepticism）
- For a general discussion of skepticism, see Skepticism.
Philosophical skepticism (UK spelling scepticism; from Greek σκέψις skepsis, "inquiry") is both a philosophical school of thought and a method that crosses disciplines and cultures.
It is generally agreed that knowledge requires justification. It is not enough to have a true belief: one must also have good reasons for that belief. Skeptics claim that it is not possible to have an adequate justification.