s soon as those circumstances differ the resulting form
differs too. The offspring is like its parent, not because it includes
an immortal typical form, but because it is exposed in development to
the same conditions as was its parent. Elsewhere I have endeavoured to
show that we must acknowledge this absolute dominion of physical agents
over organic forms as the fundamental principle in all the sciences of
organization; indeed, the main object of my work on Physiology was to
enforce this very doctrine. But such a doctrine is altogether
inconsistent with the Ideal theory of Platonism. It is no latent
imperishable type existing from eternity that is dominating in such
developments, but they take place as the issue of a resistless law,
variety being possible under variation of environment. Hence we may
perhaps excuse ourselves from that suprasensual world in which reside
typical forms, universals, ideas of created things, declining this
complex machinery of Platonism, and substituting for it a simple notion
of law. Nor shall we find, if from this starting-point we direct our
thoughts upward, as Plato did from subordinate ideas to the first idea,
anything incompatible with the noble conclusion to which he eventually
came, anything incompatible with the majesty of God, whose existence and
attributes may be asserted with more precision and distinctness from
considerations of the operation of immutable law than they can be from
the starting-point of fantastic, imaginary, ideal forms.

[Sidenote: Rise of the Sceptics.]

We have seen how the pre-Socratic philosophy ended in the Sophists; we
have now to see how the post-Socratic ended in the Sceptics. Again was
repeated the same result exhibited in former times, that the doctrines
of the different schools, even those supposed to be matters of absolute
demonstration, were not only essentially different, but in contradiction
to one another. Again, therefore, the opinion was resumed that the
intellect of man possesses no criterion of truth, being neither able to
distinguish among the contradictions of the impressions of the senses,
nor to judge of the correctness of philosophical deductions, nor even
to determine the intrinsic morality of acts. And, if there be no
criterion of truth, there can be no certain ground of science, and there
remains nothing for us but doubt. Such was the conclusion to which
Pyrrho, the founder of the Sceptics, came. He lived about B.C. 300. His
philosop