1p33sc1.md (1175B)
1 As I have thus shown, more clearly than the sun at 2 noonday, that there is nothing to justify us in calling things 3 contingent, I wish to explain briefly what meaning we shall 4 attach to the word contingent; but I will first explain the 5 words necessary and impossible. 6 7 A thing is called necessary either in respect to its essence 8 or in respect to its cause; for the existence of a thing 9 necessarily follows, either from its essence and definition, or 10 from a given efficient cause. For similar reasons a thing is 11 said to be impossible; namely, inasmuch as its essence or 12 definition involves a contradiction, or because no external cause 13 is granted, which is conditioned to produce such an effect; but 14 a thing can in no respect be called contingent, save in relation 15 to the imperfection of our knowledge. 16 17 A thing of which we do not know whether the essence does or 18 does not involve a contradiction, or of which, knowing that it 19 does not involve a contradiction, we are still in doubt 20 concerning the existence, because the order of causes escapes 21 us,–such a thing, I say, cannot appear to us either necessary or 22 impossible. Wherefore we call it contingent or possible. 23 24