=169.= It was a favourite contention of Cicero, adopted from his teacher Antiochus, that the Stoic dialectic was no original system, but only a modification of the views of the old Academy[147]. Such a conclusion seems partly due to the fact that the Stoics of his own time had largely borrowed from the Academic system in detail; and partly to the overlooking by Antiochus of an essential difference of spirit between the two schools. Plato is speculative, Zeno positive; Plato plays with a dozen theories, Zeno consistently adheres to one. Plato ranks the mind high, Zeno the will; Plato bases his system on the general concept, Zeno on the individual person or object. It would seem that no contrast could be more complete. Nor does Zeno’s theory agree with that of Epicurus. Both indeed are positive teachers, and hold that the senses are messengers of truth. But here Epicurus stops, whilst Zeno goes on. We have to understand rightly the functions and limitations of the senses, or we shall quickly glide into error; we have also to learn that the senses are but servants, and that the mind rules them as a monarch by divine right, coordinating the messages they bring, shaping them according to its own creative capacity, even adding to them from the material it has derived from its source. The Stoic theory is in fact a bold survey of the results of the reflection of the human mind upon its own operations; it has, as we might expect, many gaps, a good deal of overlapping description, and some inconsistencies. To sceptical objections it is of course unable to give answers which are logically satisfactory; but its general position proved acceptable to men who sought in philosophy a guide to practical life. [Sidenote: Questions of temperament.]