explanations, they appeal to principles as dogmatic as those of any religious creed or confession. It does not follow that these principles are fundamentally wrong, but they are not progressive; how far, for instance, their application in Physiology to distinctively vital processes is justified, though it is an extremely difficult question, is one quite open to discussion. We have no need here to inquire into this matter; it is enough if we see the significance of the fact that the growth of knowledge is only possible through struggle, conflict, and opposition overcome; we may say of knowledge, sub pondere crescit,-a truth which has been beautifully expressed by James Russell Lowell in one of his sonnets:

"The hope of Truth grows stronger day by day;
I hear the Soul of Man around me waking,
Like a great sea, its frozen fetters breaking,
And flinging up to heaven its sunlit spray,
Tossing huge continents in scornful play,
And crushing them, with din of grinding thunder,
That makes old emptinesses stare in wonder; . . .
For high, and yet more high, the murmurs swell
Of inward strife for truth and liberty."

In the intellectual world, as in the physical, there is no progress without conflict, criticism, and competition; in the realm of ideas we see unmistakably a struggle for existence, a natural selection' and 'survival of the fittest.' This is the principle which Hegel had in view in the applications of his Logic-his doctrine of Thought as a dialectically progressive movement through the meeting of opposites-to the history of human thought and endeavour in every direction; it is this that gives to his expositions of history such power as sources of instruction and enlightenment,

for those who are not destitute of the historic sense. This is true, notwithstanding the excessively rigid formalism with which the principle is applied by him in certain cases. We can never find clearly marked theses and antitheses (in pairs) from the opposition of which the higher truth springs; we can only find conflicting evepyeía, streams of tendency, movements of thought. Truth and error struggle together; or rather, one fragment of truth mingled with error contends with another fragment mingled with different errors.1 The problem is never rightly put in the form, Which of these two is right and which wrong? but in the form, Which of these two (if either) contains the more of truth? And to solve this problem, we have to find a point of view above both the conflicting principles from which to criticise them; that is, we need a principle containing more truth than either of them. The attainment of truth is only possible because many human thinkers defend different and conflicting beliefs and theories, so that here one thing is upheld, there the opposite; for without such opposition, the higher principle could never emerge,—-even the mere need for it could never be felt. It counts for nothing that this or that individual man gives up the effort, and despairs of real knowledge; human reason has an indestructible confidence in itself, and attacks its problems with renewed energy again and ever again. The irresistible, undying confidence of reason in itself, in its power of attaining to real knowledge at last, is shown by the history of human thought in all its branches,-scientific, philosophical, theological. The mind of man has

1 All generally current beliefs and theories contain, in solution as it were, fragments of truth of different sizes and shapes, which require to be precipitated.

always persisted, and seemingly always will persist, in the attempt to think consistently about the world, to make it intelligible and rational, to comprehend it somehow as a Whole. It seems to be by a native and natural impulse that all men endeavour to understand and comprehend things for the sake of understanding them; and this is the mainspring of all attempts at science of every kind. Is not this an indication strong and sure that man is greater than he seems? May we not say it speaks with no uncertain sound in favour of the faith that makes him a child of the Infinite and Eternal?

It is this incessant conflict of current modes of thought scientific, political, sociological, moral, religious-that makes Philosophy an absolute necessity for the thoughtful part of the community, or for the human race, though it may sometimes be a luxury (as it were) for the individual. The best general definition of Philosophy is probably that which describes it as an attempt to find points of view from which to judge such conflicting modes of thought, both in knowledge or theory and in practice, or an attempt to establish reliable principles by which to criticise them. These principles are not a further group of beliefs and theories, to be set beside those already current, to be used as the basis of mere hostile criticism directed upon the latter from without. Whatever 'new' truths Philosophy may bring to light are developed from the different aggregates of "what is taken to be knowledge (or reasoned and systematic thought, so far as this is a wider term than knowledge) in the thoughtful part of society to which the philosophising individual belongs"; and the principles of criticism which Philosophy seeks to establish are principles by which this development may be

effected. Hence we see the truth of the observation frequently made, that every one who thinks at all must philosophise to some extent-though generally in a more or less imperfect and unsatisfactory manner; and the two great branches of Philosophy-the theory of knowledge and the theory of ethics-endeavour to carry out the process systematically. Here, again, the condition of progress is the same; it is possible only as a result of divergence, conflict, and mutual criticism. The philosophical principles of criticism of which I have spoken can be derived only from penetrating reflection upon the essential characteristics of our nature as theoretical or cognitive, and as practical, so that divergent interpretations are always possible, and in our present state inevitable. Hence we find that a self-criticism of philosophic principles takes place, the nature of which it should be the purpose of the history of Philosophy to exhibit.

Thus every conquest of the human intellect, in the way of truer knowledge, is analogous to a survival of the fittest issuing from a struggle for existence; and the source and motive of all the effort and struggle is the conviction, indemonstrable but native to our intelligence, that the attainment of truth is one form of the highest good for man. This is sometimes expressed by saying that truth is an absolute good, or end-in-itself, in Kantian phraseology—that is, an end valued simply for being what is, and not merely as a means to something further; but what is really meant is, that the function or activity of our nature which manifests itself in the attainment and realisation of truth is an absolute good, and this, so far as it goes, is in essential harmony with the religious view of man's life and destiny; while, as we have seen, it must be recognised as the

explanation of both the existence and the progress of science.

In another respect, also, there is no discoverable variance or divergence between these two movements of thought, though the contrary is constantly assumed, and is productive of much error and confusion. I refer to the distinction of knowledge as characteristic of science, and belief or faith as characteristic of religion. The implication is that a much higher kind of certainty attaches to the conclusions of the sciences than to any distinctively religious belief. The antithesis which is supposed to hold between knowledge and belief, or reason and faith, is appealed to alike by theological apologists and anti-theological scientists,' who, though they differ in everything else, are usually quite ready to agree in the acceptance of confused but dogmatic assumptions. How thoroughly superficial this distinction is we may see if we resolutely face the question, What is truth? This is indeed the fundamental question of the Theory of Knowledge and of the higher developments of modern Logic, which is simply Reason taking knowledge of itself, becoming aware of its own structure, responding to the appeal "Know thyself!" What is the meaning of truth, certainty, knowledge? What are the general characteristics of truth, as such? Surely this question needs to be considered before we discuss what particular truths we can arrive at, or separate some kinds of knowledge from others as being in a high degree clear, sound, and reliable, while the latter are not. The purely arbitrary character of such procedure becomes evident in the light of the conclusions of recent logical inquiry.

All knowledge, in so far as it really is knowledge, is wanting in the character of certainty; this must ever