Quick Definition: Questions the possibility of certainty in knowledge
Philosophical skepticism (from Greek σκέψις, skepsis meaning “inquiry”; UK spelling scepticism) is both a philosophical school of thought and a method that crosses disciplines and cultures. Many skeptics critically examine the meaning systems of their times, and this examination often results in a position of ambiguity or doubt. This skepticism can range from disbelief in contemporary philosophical solutions, to agnosticism, to rejecting the reality of the external world. Philosophical skepticism is an old movement with many variations, and contrasts with the view that anything is certain, especially with absolute or unconditional certainty. For example, Hellenistic philosophers would claim such beliefs are dogmatism.
Philosophical skepticism is distinguished from methodological skepticism in that philosophical skepticism is an approach that questions the possibility of certainty in knowledge, whereas methodological skepticism is an approach that subjects all knowledge claims to scrutiny with the goal of sorting out true from false claims.