common language; especially as, being indifferently implied in sound and unsound thinking, they furnish no criterion by which we can distinguish the one from the other.

This view is confirmed by the history of philosophy down to the present time. While Logic, from the days of Aristotle, has been in possession of a scientific method and a definite contents, whose truth, whatever opinion may be entertained of their utility, no critic has succeeded in impugning, Metaphysics has from the same period been equally conspicuous as the changing Proteus of philosophy, whose concealed wisdom, sought after by ceaseless efforts of strength and countless varieties of artifice, has invariably eluded the inquiries of his worshippers. The union of the two, so far from contributing to the scientific completeness of the former, has only served to mar its beauty and simplicity by extralogical details, and to misrepresent its true purpose and value by obscure intimations of deeper mysteries lying hid beneath its apparent surface. On the other hand, in proportion as the true character of Logic as a science has become better known and appreciated, it has gradually been separated from Metaphysics, and been associated with Psychology. As the science of the laws of thought, it is absurd to expect that its object and character can be rightly estimated by those who are unacquainted with the nature and powers of the understanding itself,-with its re

lation to the cognate faculties and operations of the humanmind,-with its legitimate province and duties. It is only in this connection that we can hope to see Logic finally freed from the unsightly excrescences with which it has hitherto been deformed, yet still retaining a clearly defined portion of valuable scientific truth, and cultivated in a spirit of enlightened appreciation and criticism, equally removed from the blind veneration of the idolater and the blind hostility of the iconoclast. It is only in this connection that the boundaries of the two sciences can be clearly marked out, and those portions of psychological matter and phraseology whose random introduction has contributed so much to deface and obscure the pages of logical treatises, can become of inestimable value as part and parcel of a cognate and complementary, but by no means identical study. And if, in this association, it becomes necessary to abase considerably the once towering ambition of the Art of Arts and Science of Sciences, the loss is more than compensated by the substitution of a humbler indeed, but more attainable and more serviceable aim,-the knowledge of the distinct provinces to be assigned to Thought and Experience respectively, of the true value of each within its province, and its worse than uselessness beyond ;-the knowledge of ourselves and our faculties, of our true intellectual wealth, the nature of its tenure, and the conditions of its lawful increase. By such cultiva

tion alone can we hope to see Logic finally exhibited in its true character and estimated at its true value; neither encumbered with fictitious wealth by a spurious utilitarianism, nor unprofitably buried in the earth of an isolated and barren formalism.

APPENDIX.

66

Note A, p. 80.

It is much to be regretted that Dr. Whewell, who has made good use of Kantian principles in many parts of his Philosophy of the Inductive Sciences," has not more accurately observed Kant's distinction between the necessary laws under which all men think, and the contingent laws under which certain men think of certain things. His neglect of this distinction has given a seeming advantage to the empirical arguments of his antagonist, Mr. Mill, who is thus enabled apparently to decide the question at issue by what is in reality no more than an argumentum ad hominem. Thus Dr. Whewell says of certain discoveries of physical laws; "So complete has been the victory of truth in most of these instances, that at present we can hardly imagine the struggle to have been necessary. The very essence of these triumphs is that they lead us to regard the views we reject as not only false, but inconceivable." In this relation, it is obvious that the inconceivability is, with reference to the human mind, merely contingent, and relative to the particular studies of particular men. Before the days of Copernicus, men could not conceive the apparent motion of the sun on the heliocentric hypothesis: the progress of science has reversed the difficulty; but the progress of science

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itself is contingent on the will of certain men to apply themselves to it. By thus endeavouring to exalt inductive laws of matter into à priori laws of mind, Dr. Whewell has unintentionally contributed to give an undue plausibility to the opposite theory, which reduces all laws of mind into the mere associations of this or that material experience.

But on psychological grounds it would seem as if the point of separation between à priori principles and empirical generalizations ought not to be very difficult of determination. The difference is not one of degree but of kind; and the separation between the two classes of truths is such that no conceivable progress of science can ever convert the one into the other. That which is inconceivable, not accidentally from the peculiar circumstances of certain men, but universally to all, must be so in consequence of an original law of the human mind: that which is universally true within the field of experience indicates an original law of the material world. No transformation of one into the other is possible, unless the progress of science can change mind to matter or matter to mind. It is therefore incumbent on the philosopher who would extend mathematical certainty to the domain of physical science, to confirm in every instance his theory by a psychological deduction of his principles, as Kant has done in the instances of Space and Time.

Dr. Whewell lays much stress on clearness and distinctness of conceptions as the basis of the axiomatic truths of physical science. But the clearness or distinctness of any conception can only enable us more accurately to unfold the virtual contents of the concept itself: it cannot enable us to add à priori any new attribute. In other words, the increased clearness and distinctness of a conception may enable us to multiply to any extent our