icates in logic. All that exists, as contemplated by the
human mind, forms one large system or complex fact, and this of course
resolves itself into an indefinite number of particular facts, which, as
being portions of a whole, have countless relations of every kind, one
towards another. Knowledge is the apprehension of these facts, whether in
themselves, or in their mutual positions and bearings. And, as all taken
together form one integral subject for contemplation, so there are no
natural or real limits between part and part; one is ever running into
another; all, as viewed by the mind, are combined together, and possess a
correlative character one with another, from the internal mysteries of the
Divine Essence down to our own sensations and consciousness, from the most
solemn appointments of the Lord of all down to what may be called the
accident of the hour, from the most glorious seraph down to the vilest and
most noxious of reptiles.

Now, it is not wonderful that, with all its capabilities, the human mind
cannot take in this whole vast fact at a single glance, or gain possession
of it at once. Like a short-sighted reader, its eye pores closely, and
travels slowly, over the awful volume which lies open for its inspection.
Or again, as we deal with some huge structure of many parts and sides, the
mind goes round about it, noting down, first one thing, then another, as
it best may, and viewing it under different aspects, by way of making
progress towards mastering the whole. So by degrees and by circuitous
advances does it rise aloft and subject to itself a knowledge of that
universe into which it has been born.

These various partial views or abstractions, by means of which the mind
looks out upon its object, are called sciences, and embrace respectively
larger or smaller portions of the field of knowledge; sometimes extending
far and wide, but superficially, sometimes with exactness over particular
departments, sometimes occupied together on one and the same portion,
sometimes holding one part in common, and then ranging on this side or
that in absolute divergence one from the other. Thus Optics has for its
subject the whole visible creation, so far forth as it is simply visible;
Mental Philosophy has a narrower province, but a richer one. Astronomy,
plane and physical, each has the same subject-matter, but views it or
treats it differently; lastly, Geology and Comparative Anatomy have
subject-matters partly the