opes and plans, each thing was done. Why it
was done in this manner rather than in that; why by this man rather
than by that; why it was done without any assistant, or why with this
one; why no one was privy to it, or why somebody was, or why this
particular person was; why this was done before; why this was not done
before; why it was done in this particular instance; why it was done
afterwards; what was done designedly, or what came as a consequence of
the original action; whether the speech is consistent with the facts
or with itself; whether this is a token of this thing, or of that
thing, or of both this and that, and which it is a token of most; what
has been done which ought not to have been done, or what has not been
done which ought to have been done.

When the mind considers every portion of the whole business with this
intention, then the topics which have been reserved, will come into
use, which we have already spoken of; and certain arguments will
be derived from them both separately and unitedly. Part of which
arguments will depend on what is probable, part on what is necessary;
there will be added also to conjecture questions, testimony, reports.
All of which things each party ought to endeavour by a similar use of
these rules to turn to the advantage of his own cause. For it will be
desirable to suggest suspicions from questions, from evidence, and
from some report or other, in the same manner as they have been
derived from the cause, or the person, or the action.

Wherefore those men appear to us to be mistaken who think that this
kind of suspicion does not need any regular system, and so do those
who think that it is better to give rules in a different manner about
the whole method of conjectural argument. For all conjecture must be
derived from the same topics; for both the cause of every rumour and
the truth of it will be found to arise from the things attributed to
him who in his inquiry has made any particular statement, and to him
who has done so in his evidence. But in every cause a part of the
arguments is joined to that cause alone which is expressed, and it is
derived from it in such a manner that it cannot be very conveniently
transferred from it to all other causes of the same kind; but part
of it is more rambling, and adapted either to all causes of the same
kind, or at all events to most of them.

XV. These arguments then which can be transferred to many causes,
we call common topics. F