y of life in the simplest manner, and at the
cost of the least complexity of structure and function; while the lowest
is that which yields the least quantity at the greatest cost; and
between these two extremes organisms will be ranked by the ratio of
their complexity to their life-productivity--life being measured
mathematically (as something homogeneous) by its vigour, by its
duration, and by the amount of matter animated, whether in the
individual or in its progeny. It is obvious how, at this rate, our
zoological hierarchy is turned topsy-turvy; and how difficult it will be
to show that man is a better life-machine than, say, a mud-turtle with
its centuries of vital existence.

It would be a monstrous allegation to say that any evolutionist would
defend these conclusions in all their crudity; but is only by thus
pushing implied principles to their results, that their incoherence can
be made plain. Once more, if this simple uniform thing called life be
the sole cause, determining organic Evolution and selecting accidental
variations, just in so far as they favour its own maintenance and
multiplication, then every organ, appliance, and faculty by which man
differs from the simplest bioplast, is merely a life-preserving
contrivance. To speak human-wise, Nature in that case has but one
end--animal life; and chooses every means solely with a view to that
end. She does not care about pain or pleasure, or consciousness, or
knowledge, or truth, or morality, or society, or science, or religion,
for their own sakes; she cares for life only, and for these so far
as--like horns and teeth and claws--they are conducive to life.
Evolution therefore is governed by a blind non-moral principle--as blind
and ruthless as gravitation. This being so, the mind is for the sake of
the body, and not conversely. Evolution is not making for truth and
righteousness as for greater or even as for co-ordinate ends; but simply
for life, to which sometimes truth and righteousness, but just as often
illusion and selfishness, are means. There is nothing therefore in this
process of Nature to make us trust that our mind really makes for truth
as such, or that it has any essential tendency to greater correspondence
with reality, beyond what subserves to fuller animal existence. The fact
that a certain belief makes animal life possible is no proof of its
truth, but only of its expediency. The extent to which many pleasures
depend on illusion is proverbial