Democritus sometimes does away with what appears to the senses, and says that none of these appears according to truth but only according to opinion: the truth in real things is that there are atoms and void. 'By convention sweet', he says, 'by convention bitter, by convention hot, by convention cold, by convention colour: but in reality atoms and void.'
Sextus EmpiricusThe Mode of circular reasoning is the form used when the proof itself which ought to establish the matter of inquiry requires confirmation derived from the matter; in this case, being unable to assume either in order to establish the other, we suspend judgement about both.
Sextus EmpiricusThe skeptic, being a lover of his kind, desires to cure by speech, as best he can, the self-conceit and rashness of the dogmatists.
Sextus EmpiricusScepticism is an ability, or mental attitude, which opposes appearances to judgments in any way whatsoever, with the result that,owing to the equipollence of the objects and reasons thus opposed we are brought firstly to a state of mental suspense and next to a state of "unperturbedness" or quietude.
Sextus Empiricus