it. They
know full well that the chemist now prepares from inorganic matter a
vast array of substances, which were some time ago regarded as the
sole products of vitality. They are intimately acquainted with the
structural power of matter, as evidenced in the phenomena of
crystallisation. They can justify scientifically their belief in its
potency, under the proper conditions, to produce organisms. But, in
reply to your question, they will frankly admit their inability to
point to any satisfactory experimental proof that life can be
developed, save from demonstrable antecedent life. As already
indicated, they draw the line from the highest organisms through lower
ones down to the lowest; and it is the prolongation of this line by
the intellect, beyond the range of the senses, that leads them to the
conclusion which Bruno so boldly enunciated. [Footnote: Bruno was a
Pantheist,' not an 'Atheist' or a 'Materialist.']

The 'materialism' here professed may be vastly different from what you
suppose, and I therefore crave your gracious patience to the end. 'The
question of an external world,' says J. S. Mill, 'is the great
battleground of metaphysics.' [Footnote: 'Examination of Hamilton,' p.
154.] Mr. Mill himself reduces external phenomena to 'possibilities
of sensation.' Kant, as we have seen, made time and space 'forms' of
our own intuitions. Fichte, having first by the inexorable logic of
his understanding proved himself to be a mere link in that chain of
eternal causation which holds so rigidly in nature, violently broke
the chain by making nature, and all that it inherits, an apparition of
the mind. [Footnote: 'Bestimmung des Menschen.'] And it is by no
means easy to combat such notions. For when I say 'I see you,' and
that there is not the least doubt about it, the obvious reply is, that
what I am really conscious of is an affection of my own retina. And
if I urge that my sight can be checked by touching you, the retort
would be that I am equally transgressing the limits of fact; for what
I am really conscious of is, not that you are there, but that the
nerves of my hand have undergone a change.

All we hear, and see, and touch, and taste, and smell, are, it would
be urged, mere variations of our own condition, beyond which, even to
the extent of a hair's breadth, we cannot go. That anything answering
to our impressions exists outside of ourselves is not a fact, but an
inference, to which all validity wou