Full Idea
The same oar seems bent when in the water but straight when out of the water.
Clarification
A classic example to support scepticism about our perception of reality
Gist of Idea
The same oar seems bent in water and straight when out of it
Source
Sextus Empiricus (Outlines of Pyrrhonism [c.180], I.119)
Book Reference
Sextus Empiricus: 'Outlines of Pyrrhonism', ed/tr. Bury,R.G. [Prometheus 1990], p.51