contemporaries had any genius for metaphysical speculation; while the increased attention paid to Aristotle did not extend to the fundamental principles of his system, which, even within the Peripatetic school, were so misconceived as to be interpreted in a thoroughly materialistic sense.[261] A distinct parallelism may be traced in the lines of evolution along which we have accompanied our two opposing schools. While the Academicians were coming over to the Stoic theory of cognition, the Stoics themselves were moving in the same general direction, and seeking for an external reality more in consonance with their notions of certainty than the philosophy of their first teachers could supply. For, as originally constituted, Stoicism included a large element of scepticism, which must often have laid its advocates open to the charge of inconsistency from those who accepted the same principle in a more undiluted form. The Heracleitean flux adopted by Zeno as the physical basis of his system, was much better suited to a sceptical than to a dogmatic philosophy, as the use to which it was put by Protagoras and Plato sufficiently proved; and this was probably the reason why Boêthus and Panaetius partially discarded it in favour of a more stable cosmology. The dialectical studies of the school also tended to suggest more difficulties than they could remove. The comprehensive systematisation of Chrysippus, like that of Plato and Aristotle, had for its object the illustration of each topic from every point of view, and especially from the negative as well as from the positive side. The consequence was that his indefatigable erudition had collected a great number of logical puzzles which he had either neglected or found himself unable to solve. There would, therefore, be a growing inclination to substitute a literary and rhetorical for a logical training: and as we shall presently see, there was an extraneous influence acting in the same direction. Finally, the rigour of Stoic morality had been strained to such a pitch that its professors were driven to admit the complete ideality of virtue. Their sage had never shown himself on earth, at least within the historical period; and the whole world of human interests being, from the rational point of view, either a delusion or a failure, stood in permanent contradiction to their optimistic theory of Nature. The Sceptics were quite aware of this practical approximation to their own views, and sometimes took advantage of it to turn the tables on their opponents with telling effect. Thus, on the occasion of that philosophical embassy with an account of which the present chapter began, when a noble Roman playfully observed to Carneades, ‘You must think that I am not a Praetor as I am not a sage, and that Rome is neither a city nor a state,’ the great Sceptic replied, turning to his colleague Diogenes, ‘That is what my Stoic friend here would say.’[262]