Meantime a formidable intellectual force had appeared in Scotland, in argumentative collision with those Germans by whom Cousin had been fascinated, and also with Cousin’s own eclectic assimilation of all philosophies. Sir William Hamilton was warning his contemporaries against the ‘masculine and brilliant’ Continental philosophy, and energetically recalling them to Reid, by two essays in the _Edinburgh Review_—one in October 1829, destructive of the ‘Philosophy of the Unconditioned,’ the other in October 1830, constructive, on Reid’s ‘Philosophy of Perception.’ The reconstruction of the philosophy of the Common Sense, contained by implication in these famous essays, was, in 1846, elaborated in commentaries which embrace the literature of philosophy, in Hamilton’s _Reid_. The Glasgow professor re-appeared in the company of the most learned of all Scottish philosophers, educated especially by Aristotle and his commentators, by Kant, and by Reid himself, whose modest enterprise was now measured by the profoundest problems and most comprehensive conceptions of ancient and modern speculation. The magnificent intellect of Hamilton raised deep questions among us that lay dormant in Reid. Hamilton in Scotland is so far in parallel with Cousin in France, that—moving in opposite directions—they both helped to _germanise_ the philosophy which makes its last appeal to the common sense. Cousin, dissatisfied with the ‘timidity’ of Reid, tried to reconcile a philosophy that should comprehend the Infinite with the philosophy that is confined to experience. Hamilton’s mission was to clip the wings of the speculative adventurers. This made him put the emphasis on the inadequacy of a human understanding for fully coping with the eternal reality. While he praised Reid for making the Common Sense in its integrity the necessary criterion of philosophy, he claimed for himself the special credit of distinguishing its necessities as of two sorts—the one a positive power, the other the impotence implied in finite intelligence. Hence human experience rests on a conditioned, or (so far) paralysed intelligence; and if omniscience only can be called ‘knowledge,’ while to know ‘in part,’ therefore with involved mysteries, must be called ignorance—it follows that man knows nothing. Ignorance is then the consummation of human philosophy, and its highest attainment is this discovery. ‘Our dream of knowledge is a little light rounded with darkness.’ ‘The highest reach of science and philosophy is the scientific recognition of human ignorance.’ ‘Doubt is the beginning and the end of all our efforts to know.’ ‘The last and highest consecration of all true religion is an altar to the unknown and unknowable God.’ Man’s knowledge of existence must be relative to his limited experience and intelligence.