here is no wonder. Wonder is
the child of knowledge--of partial and imperfect knowledge, to be
sure, but still, of knowledge. The very first step in Science is to
make an inventory of external Nature (and by and by of the faculties
of the mind that thinks). The second step is to catalogue similar
appearances together. It is a much higher flight to seek the causes of
likenesses thus discovered.

A few of the chapters of this volume are items in a mere catalogue of
wonders, and deserve their place by accurate and eloquent description.
Most of them, however, represent higher stages of insight. In the
latter, Nature is viewed not only with the eye of the observer, but
also with the mind's eye, curious to discover the reasons for things
seen. The most penetrating inward inquiry accompanies the acutest
external observation in such chapters as those of Darwin and Huxley,
here reprinted.

Now, the point not to be overlooked is this: to Darwin and Huxley, as
to their remote and uncultured ancestors, the World--the Earth, the
Sea, the Sky--is full of wonders and of mysteries, but the wonders are
of a higher order. The problems of the thunder and of the rainbow as
they presented themselves to the men of a thousand generations ago,
have been fully solved: but the questions; what is the veritable
nature of electricity, exactly how does it differ from light, are
still unanswered. And what are simple problems like these to the
questions: what is love; why do we feel a sympathy with this person,
an antipathy for that; and others of the sort? Science has made almost
infinite advances since pre-historic man first felt the feeble current
of intellectual curiosity amid his awe of the storm; it has still to
grow almost infinitely before anything like a complete explanation
even of external Nature is achieved.

Suppose that, at some future day, all physical and mechanical laws
should be found to be direct consequences of a single majestic law,
just as all the motions of the planets are (but--are they?) the direct
results of the single law of gravitation. Gravitation will, probably,
soon be explained in terms of some remoter cause, but the reason of
that single and ultimate law of the universe which we have imagined
would still remain unknown. Human knowledge will always have limits,
and beyond those limits there will always be room for mystery and
wonder. A complete and exhaustive explanation of the world is
inconceivable, so long as hum