It may be true that we cannot claim for Ferrier complete originality in his thinking; work on very similar lines was being carried on elsewhere. It is not difficult to trace throughout his writings the mode of his development. The earlier works are evidently influenced by Fichte and his school, since the personal ego and individual freedom figure as the principal conceptions in our knowledge; and even while the Scottish school of psychologists is being combated, the influence of Hamilton is very manifest. But as time goes on, Ferrier's ideas become more concrete; the theory of consciousness becomes more absolute in its conception; the human or individual element is less conspicuous as the universal element is more, which signifies that gradually he approaches closer to the standpoint of the later German thinkers by a careful study of their works, though for the most part it is Reid and Hamilton his criticisms have in view, and not the corresponding work of Kant.

Still, we should say that Ferrier's attitude represented another phase in the same struggle against abstraction and towards unity in knowledge, rather than being a simple outcome of the German influence in Scotland. This last assumption he at least repudiated with energy, and boldly claimed to have developed and completed his system for himself. He claimed to have worked on national lines; to have started from the philosophy of his country as it was currently accepted, and to have little difficulty in proving from itself its absolute inadequacy. He felt that in his doctrine of the reality of knowledge he had found the means of solving problems hitherto dark and obscure, and he used his instruments bravely, and on the whole successfully.

The faith-philosophy which professed to know reality through the senses, when these senses were a part of the external universe, or signified taking for granted the matter in dispute, was utterly repugnant to Ferrier. The Unknowable of Sir William Hamilton was inconceivable to him, and he ever kept this theory and its errors in his mind, while developing a system of his own. It is better that a philosophic system should grow up thus, instead of coming to us from without in language hard to understand because of foreign idioms and unwonted modes of expression. To be of use, a philosophy should speak the language of the people: until it becomes identified with ordinary ways of thinking, its influence is never really great; and the Idealism of Germany has in this country always suffered from being intelligible only to the few. Therefore we hold all credit due to Ferrier for consistently refusing to adopt the phraseology of a foreign country, and setting himself, heart and soul, to find expression for his thoughts in the language of his birth.

Ferrier introduces his Lectures on Greek Philosophy, the last subject on which he undertook to write, in a manner which reminds us of Hegel's remarkable Introduction to his History of Philosophy; he begins, like Hegel, by pointing out that the study of philosophy is just the study of our own reason in its development, but that what is worked out in our minds hurriedly and within contracted limits, is in philosophy evolved at leisure, and seen in its just proportions: the historian of philosophy has not merely to record the existence of dead systems of thought that are past and gone, but the living products of his own, full of present, vital interest, and there is nothing arbitrary or capricious in such a history: all is reasoned thought as it manifests and reveals itself.

Philosophy, Ferrier defines, by calling it the pursuit of Truth—not relative Truth, but absolute, what necessarily exists for all minds alike; and man's faculties (contrary to what is generally supposed) are competent to attain to it, provided only that they have something in common with all other minds, i.e., are partakers in a universal intelligence. He works this out in his Introduction in an extremely interesting way, showing, as he does, how in all intelligence there must be a universal, a unity; that the very essence of religion, for example, rests on the unity which constitutes the bond between God and man, and that when this is denied, religion is made impossible. What then, we may ask, is the Truth that has to be pursued?

It is that which is the real, the object of philosophy—the real which exists for all intelligence. The historian of philosophy must show that philosophy in its history corresponds with this definition, if the definition be a true one.

The lectures begin with Thales and the followers of the Ionic school, and Ferrier points out how, in spite of the material elements which are taken as a basis, their systems are philosophic, in so far as they aim at the establishment of a universal in all things, and carry with them the belief that this universal is the ultimately real; and this gives them an interest which from their sensuous forms we could hardly have expected to find. But it was Heraclitus' doctrine of Becoming that was most congenial to Ferrier, as it was to his great predecessor Hegel. Being and Not-Being, the unity of contraries as essential sides of Truth, in such conceptions as these Ferrier believes we come nearer to the truth of the universe than in the current views of philosophy, in which the unity of contrary determinations in one subject is regarded as impossible. Apart, either side is incomprehensible, and hence Mr. Mansel and Sir William Hamilton argue the impotence of human reason; but if, as Ferrier believes, they are shown to be but moments or essential factors in conception, the antagonism will be proved unreal—it will be an antagonism proper to the very life and essence of reason.

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.

A philosophic article, entitled Berkeley and Idealism, and published in June of 1842, was designed to meet the attack of Mr. Samuel Bailey, who had written a Review of Berkeley's Theory of Vision, criticising the soundness of his views. Mr. Bailey replied, and Ferrier a year later published an article on that reply. Ferrier rightly appreciates the very important place which ought to be allowed to Berkeley as a factor in the development of philosophic truth—a place which has only been properly understood in later years. He saw the part he had played in bringing the real significance of Absolute Idealism into view, and deprecated the representation of his system made by David Hume, or the popular idea that Berkeley denied all reality to matter. What he did deny was the reality which is supposed to lie beyond experience, and his criticism in this regard was invaluable as a basis for a future system. In his own words, he did not wish to change things into ideas, but ideas into things: matter could not exist independently of mind. But yet Ferrier is perfectly aware that Berkeley did not entirely grasp the absolute standpoint that the thing is the appearance, and the appearance is the thing. Regarded merely as a literary production, this article is entitled to rank with the classics of philosophic writings both as regards the beauty of its style and its logical development. Ferrier does not often touch directly on questions of religion or theology, but there is an interesting passage in this essay which shows his views regarding the question of immortality. He is talking of the impossibility of our ever conceiving to ourselves the idea of our annihilation. Such an idea could not be rationally articulated. We appear, indeed, to be able to realise it, but we only think we think it: real thought of death in this sense would involve our being already dead; but in thought we are and must be immortal. 'We have nothing to wait for; eternity is even now within us, and time, with all its vexing troubles, is no more.'