ism, which is essentially a modern doctrine,
does not begin with rhapsodies, but with a very sober analysis of
familiar truths, conducted by the most sober of all philosophers,
Immanuel Kant. This philosopher lived in Konigsberg, Germany, at the
close of the eighteenth century. He is related to absolute idealism much
as Socrates is related to Platonism: he was not himself speculative, but
employed a critical method which was transformed by his followers into a
metaphysical construction. It is essential to the understanding both of
Kant and of his more speculative successors, to observe that he begins
with the recognition of certain non-philosophical truths--those of
_natural science_ and _the moral consciousness_. He accepts the order of
nature formulated in the Newtonian dynamics, and the moral order
acknowledged in the common human conviction of duty. And he is
interested in discovering the ground upon which these common
affirmations rest, the structure which virtually supports them as types
of knowledge. But a general importance attaches to the analysis because
these two types of knowledge (together with the aesthetic judgment,
which is similarly analyzed) are regarded by Kant as coextensive with
experience itself. The _very least experience_ that can be reported upon
at all is an experience of nature or duty, and as such will be informed
with their characteristic principles. Let us consider the former type.
The simplest instance of nature is the experience of the single
perceived object. In the first place, such an object will be perceived
as in space and time. These Kant calls the _forms of intuition_. An
object cannot even be presented or given without them. But, furthermore,
it will be regarded as substance, that is, as having a substratum that
persists through changes of position or quality. It will also be
regarded as causally dependent upon other objects like itself.
Causality, substance, and like principles to the number of twelve, Kant
calls the _categories of the understanding_. Both intuition and
understanding are indispensable to the experience of any object
whatsoever. They may be said to condition the object in general. Their
principles condition the process of making something out of the manifold
of sensation. But similarly, every moral experience recognizes what Kant
calls _the categorical imperative_. The categorical imperative is the
law of reasonableness or impartiality in conduct, requiring the
ind