But among them all Aristotle stands out as the “master of those that knew”--the man who attained in the Middle Ages such celebrity and authority that he narrowly escaped being canonised as a saint in the Roman calendar. If that distinction really belonged to the benefactors of mankind, I know not that any man ever lived who had a better claim to it. For his life and activity mark an epoch not only in the progress of many sciences, but in the general culture of the human mind, to which I know no parallel. He was brought up under the influence of the Socratic method of inquiry as perfected by Plato, but, though in some popular works (now lost) he adopted the dialogue as the correct method of teaching, there can be no doubt that the sober and practical tone of his mind made him despise all the delays and delights of character-drawing, and of spinning out the subject, for what we have from him is pre-eminently plain and scientific in form. There is seldom an unnecessary sentence; if there be a metaphor, it is a mere flash of colour across the cold severity of his argument. He writes like a man who had no time to waste and a vast world of subjects to teach. If it was still an age when the sciences had not entered upon the path of observation and experiment, but were philosophical speculations, Aristotle did more than any man to establish a separation between philosophy and science, while fully recognising, what in our day most scientists ignore, that positive science without a sound knowledge of philosophy is apt to run into fatal mistakes. Of course this immense programme which Aristotle set before him could not be carried out without large collaboration, and so we know that, as Plato seems to have underrated such collaboration, and thus have failed in fruitfulness among his pupils, Aristotle, who was not chosen as his successor by the school (I suppose as usual there were jealousies among the commonplace and docile pupils toward the great original thinker), formed and stimulated a band of helpers, who gathered special observations in botany, mineralogy, zoölogy, physics as the science of nature, and others who put into shape his views on rhetoric and on poetry, on ethics and on theology. We have, in my opinion, a new specimen of such delegated work in the now famous _Constitution of Athens_, which was known and quoted as Aristotle’s through later antiquity, but which is rather the work of a pupil and not a brilliant one. But then we know that Aristotle either wrote or brought out 158 of these tracts on Greek constitutions. To this I shall return in a subsequent lecture.