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.