Pascal's Pensées

Against Scepticism.—[ ... It is, then, a strange fact that we cannot define these things without obscuring them, while we speak of them with all assurance.] We assume that all conceive of them in the same way; but we assume it quite gratuitously, for we have no proof of it. I see, in truth, that the same words are applied on the same occasions, and that every time two men see a body change its place, they both express their view of this same fact by the same word, both saying that it has moved; and from this conformity of application we derive a strong conviction of a conformity of ideas. But this is not absolutely or finally convincing, though there is enough to support a bet on the affirmative, since we know that we often draw the same conclusions from different premisses.

This is enough, at least, to obscure the matter; not that it completely extinguishes the natural light which assures us of these things. The academicians[153] would have won. But this dulls it, and troubles the dogmatists to the glory of the sceptical crowd, which consists in this doubtful ambiguity, and in a certain doubtful dimness from which our doubts cannot take away all the clearness, nor our own natural lights chase away all the darkness.