The result of the inquiry into the solutions of the problem offered in the past is to show that they are all inadequate to explain and to give an ideal to the whole of life. Perplexed as to the truth of the existence of a higher world, man looked to the natural world for a firm basis to life. Here he failed to find rest—rather, indeed, he found less security than he had previously felt, for did not naturalism make of him a mere unconscious mechanism, and deny the very existence of his soul? Then he turned to humanity, and the opposing tendencies of socialism and individualism came into evidence. Each hindered the other, each shook his traditional beliefs, and each failed to give him a satisfactory goal for life. Socialism concerned itself with external social relations, but it gave life no soul. Then individualism confined man to his own resources, and there resulted an inner hollowness which became painfully evident. Socialism and individualism fail to provide a sure footing. Instead of finding certainty, man has fallen into a still deeper state of perplexity.

What shall he do? Must he once again leave the realistic systems of Naturalism, Socialism, and Individualism, and return to the older systems of Religion and Idealism? Was he not wrong in giving up the thought of a higher invisible world? Has not the restriction of life to the visible world robbed life of its greatness and dignity? This it certainly has done, and there is little wonder that the soul of mankind is already revolting, and shows a tendency once again to look towards religion and idealism for a solution of life.

But the educated mind can never again take up exactly the same position as it once did in regard to religion and idealism. The great realistic theories have made too great a change in the standard of life, and in man himself, to make it possible for him to revert simply to the old conditions, and the older orthodox doctrines of religion can never again be accepted as a mere matter of course. But the great question has again come to the forefront—is there a higher world, or is the fundamental truth of religion a mere illusion? This is the question that calls for answer to-day, an answer which must be different, as man is different, from the answers that were given in the past. A satisfactory answer is impossible without understanding clearly the relation between the Old and the New, and without taking account of the great, if partial, truths that the realistic schemes of life have taught mankind.

To accept unreservedly Naturalism, Socialism, and Individualism is impossible, for these rob life of its deeper meaning. To return to the older doctrines without reserve is equally impossible.

Shall we ignore the question? This would be a fatal mistake. Some throw themselves into the rush of work, and endeavour to forget the deeper problems of life—but "the result is a life all froth and shimmer, lacking inward sincerity, a life that can never in itself satisfy them, but only keep up the appearance of doing so." There must be some decision; for is not society being more and more broken up into small sections, possessing the most variable standards of life, and evaluating things in a diversity of ways? Such an inward schism must weaken any effort on the part of humanity to combine for ideal ends. Perhaps he of narrow vision, who sees nothing in life but sensuous pleasure, is happy—but it is the happiness of the lower world. Perhaps, too, he of the superficial mind is happy, who sees no deep contradictions in the solutions offered, and is prepared to accept one to-day and another tomorrow—but his happiness is that of the feeble mind.

What then can be done? Shall we despair? Never! The question is far too urgent. To despair is to accept a policy that spells disaster to the human race. The immediate environment is powerless to give life any real meaning. We must probe deeper into the eternal—and it is from such investigations that Eucken outlines a new theory of life.

But before we proceed to deal with Eucken's contribution to the problem, it will be profitable to stay awhile to consider how it is that we can obtain truth at all, and what are the tests that we can apply to truth when we think we have attained it. It is the problem of the possibility of knowledge, really, that we have to discuss in brief. Eucken himself does not pay much direct attention to this difficult question, for, as has been already pointed out, he refuses to be drawn from his main problem. It is impossible, however, to appreciate Eucken without understanding clearly the position he takes up in this matter.

What is truth? How can we know?—these are entrancing problems for the profound thinker, and have been written upon frequently and at great length. But we can do little more at present than give the barest outline of the positions that have been taken up. Every search for truth must assume a certain position in this matter; in studying Eucken's philosophy it is of the first importance—more so perhaps than in the case of most other philosophers—to keep in mind clearly from the outset the position he implicitly assumes.

The simplest theory of knowledge is that of Empiricism, which holds that all knowledge must be gained through experience of the outside world, and of our mental states. We see a blue wall, we obtain through our eyes an impression of blueness, and are able to make a statement: "This wall is blue." This, of course, is one of the simplest assertions that can be made, and consists merely in assigning a term—"blue"—the meaning of which has already been agreed upon, to a colour that we appear to see on a wall. The test of the truth of this assertion is a simple one—it is true if it corresponds with fact. If the same assertion is made in regard to a red wall, then it is obviously untrue. Our sense impressions give rise to a great variety of such expressions. We state "the wall is blue" as a result of an impression obtained through the organs of sight; then we speak of a pungent smell, a sweet taste, a harsh sound, or a rough stone, on account of impressions received respectively through the organs of smell, taste, hearing, and touch. But, of course, all such assertions are superficial in character—there is little more in them than the application of a conventional term to an observed phenomenon, they avail us little in solving the mysteries of the universe.

Strictly speaking, this is for the empiricist the limit of possible knowledge, but he would be a poor investigator who would be content with this and no more. The empiricist tries to go a distinct step in advance of this. The scientist observing the path of a planet travelling round the sun, finds that its course is that of an ellipse. He studies the path of a second planet, and finds that this also travels along an elliptical orbit. Later he finds that all planets he is able to observe travel in the same kind of path—then he hazards a general statement, and says, "All planets travel round their suns in elliptical orbits." But now he has left the realm of certainty for that of uncertainty. There may be innumerable planets which he cannot observe that take a different course. He hazards the general statement, because he assumes (sometimes without knowing that he does so) that nature is uniform and constant, that it will do to-day as it did yesterday, and does in infinite space as it does in the visible universe.