Possibly in his account of the early Greek philosophers Ferrier may have done what many historians of philosophy have done before him, he may have read into the systems which he has been describing much more than he was entitled so to read. He may, when he is talking of the Eleatics of Heraclitus, and even of Socrates and Plato, have had before his mind the special battle which he had chosen to fight--the battle against sensationalism in Scotland, against materialism in the form in which he found it--rather than fairly to set before his readers an exact and accurate account of the teaching of the particular philosopher of whom he writes. But has it ever been otherwise in any history of thought that was ever written, excepting perhaps in some dryasdust compendium which none excepting those weighed down with dread of examination questions, care to peruse? Thought reads itself from itself, and if it sometimes reads the present into the past, and thinks to see it there, is there matter for surprise, or is it so very far wrong? If it tells us something of the secrets it itself conceals, it is surely telling us after all much of those that are gone. For Plato, Ferrier naturally had a very great affinity; he deals with him at length, and evidently had made a special and careful study of his writings. But the same method is applied by him to Plato as was before applied to the other Greek philosophers. 'It is not so much by reading Plato as by studying our own minds that we can find out what ideas are, and perceive the significance of the theory which expounds them. It is only by verifying in our own consciousness the discoveries of antecedent philosophers that we can hope rightly to understand their doctrines or appreciate the value and importance of their speculations.' And so Ferrier proceeds to prove the necessity for the existence of 'ideas'--of universals--as the absolute truth and groundwork of whatever is. No intelligence can be intelligent excepting by their light, and they are the necessary laws or principles on which all Being and Knowing are dependent. 'All philosophy,' he says of Plato, 'speculative and practical, has been foreshadowed by his prophetic intelligence; often dimly, but always so attractively as to whet the curiosity and stimulate the ardour of those who have chosen him as a guide.' And it was as such that Ferrier marked him out and chose him as his own. With Aristotle he had probably less in common, and his treatment both of him and of the Stoics, Epicureans, and Neo-Platonists, with which the history ends, is less sympathetic in its tone and understanding in its style. But these lectures as a whole, though never put together for printing as a book, must always be of interest to the student of philosophy.