Now, if this is so, is it certain that all knowledge of these ruling conceptions is impossible?  In other words, is the attempt to construct a philosophy absurd?  To say that it is, to deny the possibility of catching any glimpse of those regulative ideas, which determine the main tendencies of human thought, is to place the supreme directorate of the human intelligence in the hands of a necessity which, for us, is blind.  For, an order that is hidden is equivalent to chance, so far as knowledge is concerned; and if we believe it to exist, we do so in the face of the fact that all we see, and all we can see, is the opposite of order, namely lawlessness.  Human knowledge, on this view, would be subjected to law in its details and compartments, but to disorder as a whole.  Thinking men would be organized into regiments; but the regiments would not constitute an army, nor would there be any unity of movement in the attack on the realm of ignorance.

But, such is not the conclusion to which the study of human history leads, especially when we observe its movements on a large scale.  On the contrary, it is found that history falls into great epochs, each of which has its own peculiar characteristics.  Ages, as well as nations and individuals, have features of their own, special and definite modes of thinking and acting.  The movement of thought in each age has its own direction, which is determined by some characteristic and fundamental idea, that fulfils for it the part of a working hypothesis in a particular science.  It is the prerogative of the greatest leaders of thought in an age to catch a glimpse of this ruling idea when it first makes its appearance; and it is their function, not only to discover it, but also to reveal it to others.  And, in this way, they are at once the exponents of their time, and its prophets.  They reveal that which is already a latent but active power—­“a tendency”; but they reveal it to a generation which will see the truth for itself, only after the potency which lies in it has manifested itself in national institutions and habits of thought and action. After the prophets have left us, we believe what they have said; as long as they are with us, they are voices crying in the wilderness.

Now, these great ideas, these harmonies of the world of mind, first strike upon the ear of the poet.  They seem to break into the consciousness of man by the way of emotion.  They possess the seer; he is divinely mad, and he utters words whose meaning passes his own calmer comprehension.  What we find in Goethe, we find also in a manner in Browning:  an insight which is also foresight, a dim and partial consciousness of the truth about to be, sending its light before it, and anticipating all systematic reflection.  It is an insight which appears to be independent of all method; but it is in nature, though not in sweep and expanse, akin to the intuitive leap by which the scientific explorer lights upon his new hypothesis.  We can find no other law for it, than that sensitiveness to the beauty and truth hidden in facts, which much reflection on them generates for genius.  For these great minds the “muddy vesture” is worn thin by thought, and they hear the immortal music.