Full Idea
The three forms of scepticism are cartesian, Humean and Pyrrhonian. The first challenges belief by inventing sceptical scenarios; the second doubts the future; the third aims to suspend belief.
Clarification
Pyrrho of Elis lived in the fourth century BCE
Gist of Idea
Scepticism is cartesian (sceptical scenarios), or Humean (future), or Pyrrhonian (suspend belief)
Source
Robert Fogelin (Walking the Tightrope of Reason [2003], Ch.4)
Book Reference
Fogelin,Robert: 'Walking the Tightrope of Reason' [OUP 2004], p.99
A Reaction
A standard distinction is made between methodological and global scepticism. The former seems to be Cartesian, and the latter Pyrrhonian. The interest here is see Hume placed in a distinctive category, because of his views on induction.