since that is a class of argument which turns principally on
resemblance, in reprehending the adversity it will be advisable to
deny that there is any resemblance at all to the case with which it is
attempted to institute the comparison. And that may be done if it
be proved to be different in genus or in nature, or in power, or
in magnitude, or in time or place, or with reference to the person
affected, or to the opinions generally entertained of it. And if it
be shown also in what classification that which is brought forward on
account of the alleged resemblance and in what place too the whole
genus with reference to which it is brought forward, ought to be
placed. After that it will be pointed out how the one thing differs
from the other, from which we shall proceed to show that a different
opinion ought to be entertained of that which is brought forward by
way of comparison, and of that to which it is sought to be compared.
And this sort of argument we especially require when that particular
argumentation which is carried on by means of induction is to be
reprehended. If any previous decision be alleged, since these are the
topics by which it is principally established, the praise of those who
have delivered such decision, the resemblance of the matter which is
at present under discussion to that which has already been the subject
of the decision referred to, that not only the decision is not found
fault with because it is mentioned, but that it is approved of by
every one, and by showing too, that the case which has been already
decided is a more difficult and a more important one than that which
is under consideration now. It will be desirable also to invalidate
it by arguments drawn from the contrary topics, if either truth or
probability will allow us to do so. And it will be necessary to take
care and notice whether the matter which has been decided has any real
connexion with that which is the present subject of discussion, and
we must also take care that no case is adduced in which any error has
been committed, so that it should seem that we are passing judgment on
the man himself who has delivered the decision referred to.

It is desirable further to take care that they do not bring forward
some solitary or unusual decision when there have been many decisions
given the other way. For by such means as this the authority of the
decision alleged can be best invalidated. And it is desirable that
those arguments w