Note 129 — Chapter V · LOGIC OF THE STOICS.

(γ) Composite forms of inference. The combination of these five simple forms of inference gives rise to the composite forms of inference,129 all of which may be again resolved into their simple forms.130 Among composite forms of inference, those composed of similar parts are distinguished from those composed of dissimilar parts;131 in the treatment of the former, however, such a useless formality is displayed, that it is hard to say what meaning the Stoics attached to them.132 If two or more inferences, the conclusion of one of which is the first premiss of the other, are so combined that the judgment which constitutes the conclusion and premiss at once is omitted in each case, the result is a Sorites or Chain-inference. The rules prescribed by the Peripatetics for the Chain-inference are developed by the Stoics with a minuteness far transcending all the requirements of science.133 With these (δ) Inference from a single premiss. composite forms of inference Antipater contrasted other forms having only a single premiss,134 but it was an addition to the field of logic of very doubtful worth. On a few other points connected with the Stoic theory of illation, we have very imperfect information.135 The loss, however, is not to be regretted, seeing that in what we already possess there is conclusive evidence that the objections brought against the Stoic logic were really well deserved, because of the microscopic care expended by them on the most worthless logical forms.136