placed in its proper genus, or is not proper, must be observed from places spoken about genus and property.
It remains, then, to declare how we must institute an inquiry, whether a thing is not defined, or whether it is not rightly defined; first, indeed, then we must see whether it is not rightly defined, since it is easier to do any thing (merely), than to do it well. Now it is clear that an error is more frequent about this, because it is more difficult, so that reasoning about this is easier than about that.
Of the (question of defining) not rightly, there are two parts, one whether obscurity is employed in the interpretation, (since it is necessary that the person defining should make use of the clearest possible interpretation, as definition is assigned, for the sake of knowledge,) and the other, whether he has stated the definition more extensively than is requisite, as every thing added in the definition is superfluous. Again, each of the above-named is divided into many parts.
Chapter 2
One place, then, belonging to the obscure is, if what is stated is equivocal with any thing, as that generation is a leading to substance, and that health is the harmony of hot and cold, for (the words) leading and harmony are equivocal, therefore it is doubtful which of the things signified, by what is multifariously predicated, a person wishes to assert. In like manner also, if when the thing defined is multifariously predicated, a person expresses himself without distinction, as it will be dubious of what he has given the definition, and it is possible to cavil, as if the definition were not adapted to every thing of which he has given the definition. Now, such a thing it is especially possible to do, when there is latent equivocation, and also it is possible, when a person has distinguished in how many ways what is assigned in the definition is predicated, to form a syllogism: for if it is not sufficiently stated in any mode, it is clear that it has not been defined according to that mode.
