ing in the unity of system his philosophical opinions, whether metaphysical or logical. This omission, considering the character of his mind, is certainly very remarkable. He was impelled by the constitution of his intellect to the search after profound principles which admitted of the widest application; such principles he reached, and they were the objects of his habitual reflection. The cast of his mind, moreover, was eminently orderly and systematic, yet he has left his readers to gather together for themselves, and form a system of his philosophical doctrines, from fragmentary and occasional communications, which, however, it should be observed, approach the highest perfection of their kind. For the absence of any systematic treatise by Sir W. Hamilton on philosophy, a variety of reasons might be alleged; such as, the comparative irksomeness of the detailed application of principles experienced by many minds capable of discovering them, the singularly elevated ideal of a philosophical work which he cherished, and severe bodily illness, which occurred at the time when he might have been expected to commence the undertaking. But even in the absence of a work of this kind, the name of Sir W. Hamilton is to be found in the foremost rank of the philosophers who have adorned the first half of the present century—a period peculiarly rich in men of great speculative ability. Probably no writer on philosophical questions since Leibnitz, with whom Sir W. Hamilton has many points in common, has been so influential, or earned so high a name by fragmentary and desultory publication. The extraordinary mental activity which characterized Sir W. Hamilton, and which carried him into many departments of investigation beyond philosophy proper, was not conjoined with an equal facility in composition, or apparently with any strong desire to awaken a general public sympathy in the results of his researches. He studied, investigated, and reflected from first to last, for the sake simply of an interest in the profound questions which occupied him. No man ever worshipped at the shrine of speculative philosophy with simpler heart, more single eye, or truer faith. For him the pleasures arising from an interest in philosophical questions, and from the ardent search after a solution of them, were intense, as these motives were all-sufficient and unmixed by any baser alloy. His was a soul that dwelt apart from petty ambitions and narrow ends, absorbed in pursuits that brought with them no material gain, capable by itself of sustaining its energies in full vitality, even before other minds had been educated by him to sympathy with his work, and scornful of inferior studies, popularly regarded and denominated useful, merely because their range is lower and narrower, and their advantages consequently more direct, perhaps, and more easily appreciated.
From a very early period of his studies. Sir W. Hamilton was in the habit of noting in a commonplace-book the results of his philosophical reading. This large folio embraces with extraordinary comprehensiveness and minuteness, and in a methodized form, the literature of philosophical questions. It bears ample testimony to the nature and extent of his studies, from the time when he left Oxford until the date of the publication of the first instalment of his views in speculative philosophy, in 1829. In this year appeared in the Edinburgh Review an article on the philosophical opinions of M. Victor Cousin, whose fame as a professor of philosophy in Paris was then deservedly of the highest order. From the appearance of this review we have to date the commencement of its author's speculative influence and reputation. This remarkable essay was greatly in advance of the philosophical education of our own country. In France, and on the continent generally, it attracted from the first the notice and admiration which it justly deserved. The distinguished philosopher, whose opinions were subjected to criticism—searching, trenchant, severe, yet courteous—was among the first to recognize and proclaim the eminent merit of the review. The essay on the Philosophy of the absolute, as the review of M. Cousin's work was afterwards entitled, was followed by two papers contributed to the same periodical, which were hardly less powerful or striking. The one was a review of the doctrines of Reid and Brown on the subject of external perception, and appeared in 1830; the other referring to recent publications on logical science, being a criticism chiefly of Dr. Whately's Logic, appeared in 1833. Sir W. Hamilton also contributed to the Edinburgh several articles on education, at once profound in matter and lofty in tone. To the articles on education are to be attributed in great measure the movements towards university reform, which of late years have been taking place in the English and Scottish universities.
The principal contributions of Sir W. Hamilton to the Edinburgh Review on philosophy, education, and literature, were collected and republished by their author in one volume, entitled, "Discussions on Philosophy," in 1852. In the appendix to this volume the author developes to some extent his new logical theory. His edition of Reid, with notes and dissertations, appeared in 1846. Sir W. Hamilton was occupied at the time of his death on a new edition of the works of Dugald Stewart, which he had completed, with the exception of the memoir of their author, proposed to be added to the collected works. The lectures on metaphysics and logic which Sir W. Hamilton was in the habit of delivering to his class in the university in alternate years, were published posthumously in 1859-60, under the editorial superintendence of Professor Mansel of Oxford, and Professor Veitch of St. Andrews.
The two great sources of influence by which the mind of Hamilton was most powerfully moulded, were doubtless the writings of Aristotle and Kant. The speculations of Reid had also a part, though a subordinate one, in this work. To Aristotle Hamilton is related by the extremely dialectical cast of his mind, the subtlety and minuteness of his distinctions, the prodigality of his refinements, and the precision and condensation of his philosophical style—demanding at every step, to make it living, the exercise of the reader's power of reflection. To the writings of Kant, and to the results of German speculation in general, Hamilton is largely indebted, not only for suggestions of much of what is positive in his doctrines, but even for those positions of antagonism both to Kantian and absolutist speculation which his marvellous critical power evoked from the study of these writings. His theory of the conditioned is, for example, an illustration of the latter statement. Our limits, however, do not allow of our entering into proof or detail on these points. In common with Reid, Hamilton holds firmly by fact and reality, even where these transcend philosophical comprehension, and cannot be brought within the sphere of symmetrical deduction. This is manifest from even a general view of what may be called his philosophical method; which is simply the study of consciousness in its integrity, as the supreme organon of philosophy. The facts of consciousness are to be accepted by us, not in so far only as we can make them the points in a chain of reasoned explication or demonstration; but as the co-ordinate data of an authentic testimony, which it is sufficient to show are not inconsistent with each other. Although Sir W. Hamilton was largely indebted to his predecessors, and obtained, as must be acknowledged, his doctrines more in the way of criticism of the results of others, than by direct psychological observation, he was, however, no servile borrower. The half-applied principle, the neglected truth, was grasped with a steadier and bolder hand; its full force and significance were disclosed; found inoperative, it was rendered living and fruitful by the touch of philosophical genius.
The essays on the philosophy of the absolute, perception, and logical science, contain the central principles of what is distinctive in the philosophy of their author. He exhibits these principles, moreover, in a style of great polish, lucidity, subtlety, condensation, and force. Their manner of composition is less elaborately technical than that of the dissertations appended to Reid's works, and it is more precise, accurate, and finished, than the comparatively easy style of the lectures. In matter they are in a sense fragments, but the fragments of a master—in themselves completed wholes, and whose single imperfection is that they have not received from the hand which fashioned them their appropriate place in the great, but unfinished edifice, of which they are the parts.
In psychology and metaphysics, the name of Hamilton is prominently associated with his theory of the limitation of human knowledge, as involved in his doctrine of the conditioned, and with his analysis of perception. The doctrine of the conditioned is nowhere better stated by its author than in the review of Cousin already referred to. The question between an absolute and relative doctrine of human knowledge, as put by Hamilton, resolves itself virtually into a question regarding the interpretation of the meaning of thought or knowledge, as subjected to certain essential laws, and of the object of thought as thus regulated. The object of thought, according to the assumptions of the article on Cousin, is necessarily regarded as a quantity in some form or other; and with this admission, the general conclusions at which the author arrives cannot be evaded. The practical result of the
