Kitap 11
19
Similarly all statements cannot be false, nor all true. Among many other difficulties which might be adduced as involved by this supposition there is the objection that if all statements were false, not even this proposition itself would be true; while if they were all true it would not be false to say that they are all false.
1
Every science inquires for certain principles and causes with respect to every knowable thing which comes within its scopeThis chapter corresponds to Aristot. Met. 6.1; cf. also Aristot. Met. 4.3.1-6 and ch. 4 above. It also answers the problem stated in ch. 1.2.; e.g., the sciences of medicine and physical culture do this, and so does each of the other productive and mathematical sciences. Each one of these marks out for itself some class of objects, and concerns itself with this as with something existent and real, but not qua real; it is another science distinct from these which does this.
2
Each of the said sciences arrives in some way at the essence in a particular class of things, and then tries to prove the rest more or less exactly. Some arrive at the essence through sense-perception, and some by hypothesis; hence it is obvious from such a process of induction that there is no demonstration of the reality or essence.
