heory of development was always _a mere notion, a castle in the
air_, and never could be anything more. To say that it was mere
moonshine would be to give it far too respectable a standing; for
moonshine has a real existence, and may be seen and felt. But nobody
ever saw or felt a homogeneous nebula. Indeed, its inventor never
pretended that he, or anybody else, ever saw one; or saw it sailing off
into moons, and planets, and suns, or ever would see any such thing. No
scientific man has ever pretended that it was an established fact, or
anything more than a theory, a notion. Young people, who are invited to
hazard their souls on the strength of this miscalled scientific theory,
should remember that it is not science, which means something a man
knows, but merely a theory, which is some notion which he imagines.

_It is an unsatisfactory notion._ It does not answer the purpose of its
inventors. As we have already seen, it gives us no account of the origin
of the homogeneous matter of the nebula. It gives no answer to the
questions, How did it get to be so hot, while all the space around it
was so cold? Is the fire that heated it burning still, or is it
exhausted for want of fuel? Were the germs of all the plants and animals
in it while it was blazing at a white heat? If they were, how did they
escape being burnt to ashes? If they were not, where did they come from?
For there was nothing but that nebula then in existence. Did it contain
within itself all the principles of things, all the forces now found in
the worlds which grew out of it? If so, how came they there? If not, how
did attraction, and repulsion, vegetable life, animal life, intellect,
and free will, work themselves into that cloud of homogeneous gas?

Professor Tyndall thus exposes the absurdity of the supposition that the
nebula contained the elements of mind: "For what are the core and
essence of this hypothesis? Strip it naked and you stand face to face
with the notion that not alone the more ignoble forms of animalcular or
animal life, not alone the noble forms of the horse and lion, not alone
the exquisite and wonderful mechanisms of the human body, but the human
mind itself--emotion, intellect, will, and all these phenomena, were
once latent in a fiery cloud. Surely the mere statement of such a notion
is more than a refutation."[201]

_It was only one of several contradictory notions._ Thus a writer in the
_Atlantic Monthly_, so far from accepting the