principle of unity, which, though latent, is really prior to all
explanation of particular matters of fact.

In truth, man has only one way of knowing. There is no fundamental
difference between scientific and philosophic procedure. We always light
up facts by means of general laws. The fall of the stone was a perfect
enigma, a universally unintelligible bit of experience, till the
majestic imagination of Newton conceived the idea of universal
gravitation. Wherever mind successfully invades the realm of chaos,
poetry, the sense of the whole, comes first. There is the intuitive
flash, the penetrative glimpse, got no one knows exactly whence--though
we do know that it comes neither from the dead facts nor from the vacant
region of _a priori_ thought, but somehow from the interaction of both
these elements of knowledge. After the intuitive flash comes the slow
labour of proof, the application of the principle to details. And that
application transforms both the principle and the details, so that the
former is enriched with content and the latter are made intelligible--a
veritable conquest and valid possession for mankind. And in this labour
of proof, science and philosophy alike take their share.

Philosophy may be said to come midway between poetry and science, and to
partake of the nature of both. On the one side it deals, like poetry,
with ideals of knowledge, and announces truths which it does not
completely verify; on the other, it leaves to science the task of
articulating its principles in facts, though it begins the articulation
itself. It reveals subsidiary principles, and is, at the same time, a
witness for the unity of the categories of science. We may say, if we
wish, that its principles are mere hypotheses. But so are the ideas
which underlie the most practical of the sciences; so is every forecast
of genius by virtue of which knowledge is extended; so is every