1898] Mk HERBERT SPENCERS BIOLOGY 379 
added vital principle is rejected. To the questions: Is there one 
kind of vital principle for all kinds of organisms, or is there a 
separate form for each? How are we to conceive the genesis of a 
superadded vital principle ? Under what form does it exist in the 
dessicated rotifer ?—to these questions the answers show that the 
alleged existence neither has been nor can be conceived. In attempt- 
ing, on the other hand, to realize the dynamic element as “inherent in 
the substances of the organisms displaying it, we meet with difficul- 
ties different in kind but scarcely less in degree. The processes 
which go on in living things are incomprehensible as results of any 
physical actions known to us.” “ What then,” he asks, “are we to 
say—what are we to think? Simply that in this direction, as in 
all other directions, our explanations finally bring us face to face 
with the inexplicable. The ultimate reality behind this manifesta- 
tion, as behind all other manifestations, transcends conception.” 
One must not forget, in reading the chapter on the Dynamic 
Element in Life, that it forms part of a work which is itself only a 
part of a System of Philosophy. In Biology as a science it is ques- 
tionable whether reference to the Ultimate Reality, and to noumenal 
as contrasted with phenomenal causation, is advisable. Phenomenal 
causation, as an explanation of natural occurrences, involves the 
reference of an event to a group of antecedent conditions of which 
it is the outcome. Noumenal causation, as an explanation of the 
totality of natural phenomena, involves their reference to an under- 
lying raison @étre. The one deals with a chain of antecedents and 
sequents the ends of which, and its manner of support, are beyond 
the range of our mental vision as men of science. Of the other we 
can at best know or assume that it is. The phenomenal universe 
presents us with, or rather is, a series of data. Science explains 
their connections, and leaves to philosophy a discussion of their 
noumenal origin. But since Mr Spencer here treats Biology as part 
of a System of Philosophy the ascription of phenomena to their 
noumenal origin is not out of place, though one would have thought 
that a reference to “ First Principles” should have sufficed. 
And one cannot but think that Mr Spencer’s treatment of the 
subject may render him liable to some misconception. On the first 
page of the “ Principles of Biology” there stands now, as there stood 
in 1863, the assertion that “the properties of substances though 
destroyed to sense by combination, are not destroyed in reality. It 
follows from the persistence of force, that the properties of a com- 
pound are resultants of the properties of its components—result- 
ants in which the properties of the components are severally in full 
action though mutually obscured.” Further on we are told (in sections 
added to the present edition) that living matter “ originated, as we 
must assume, during a long stage of progressive cooling,” in which 
