above-named are inherent, and that what is assigned is genus, and that the sentence is appropriate,) and besides these, that the sentence denotes the very nature of a thing, and it is necessary to do this well.
Among other things, property is especially a thing of this sort, for it is easier to subvert it, from its consisting, for the most part, of many things, and it is most difficult of confirmation, because we must combine many things, and besides, show that it is inherent in this alone, and reciprocates with a thing.
Of all however, the easiest is to confirm accident, for in others, not only inherency, but inherency thus, must be shown; but as to accident it suffices to show its inherency only. On the other hand, accident is the hardest to subvert, because the fewest things are given in it, for it is not signified in accident, over and above other things, how it is inherent, so that subversion is possible in two ways; as to the rest, either by showing non-inherency, or non-inherency in this way; but in accident, it is impossible to subvert, except by showing that it is not inherent.
The places then, through which we shall be well provided with arguments against the several problems, have almost sufficiently been enumerated.
BOOK VIII.
Chapter 1
We must next speak about order, and in what manner it is necessary to interrogate. In the first place then, he who is about to interrogate, should discover a place whence he may argue; secondly, he should interrogate and arrange the several particulars to himself; thirdly and lastly, he should advance them against another person. Now as to the discovery of the place, its consideration pertains alike to the philosopher and to the dialectician; but how to arrange these, and to interrogate, is the peculiar province of the dialectician, since the whole of this refers to another per-
