ive_ principles, the Ideas
are _regulative_ merely; their function is to guide the understanding, to
give it a direction helpful for the connection of knowledge, not to inform
it concerning the actual character of things.

Since reason is the faculty of inference (as the understanding was found to
be the faculty of judgment), the forms of the syllogism perform the same
service for us in our search for the Ideas as the forms of judgment in
the discovery of the categories. To the categorical, hypothetical, and
disjunctive syllogisms correspond the three concepts of reason, the soul or
the thinking subject, the world or the totality of phenomena, and God, the
original being or the supreme condition of the possibility of all that can
be thought. By means of these we refer all inner phenomena to the ego as
their (unknown) common subject, think all beings and events in nature as
ordered under the comprehensive system of the (never to be experienced)
universe, and regard all things as the work of a supreme (unknowable)
intelligence. These Ideas are necessary concepts; not accidental products
nor mere fancies, but concepts sprung from the nature of reason; their
use is legitimate so long as we remember that we can have a problematical
concept of objects corresponding to them, but no knowledge of these; that
they are problems and rules for knowledge, never objects and instruments of
it. Nevertheless the temptation to regard these regulative principles as
constitutive and these problems as knowable objects is almost irresistible;
for the ground of the involuntary confusion of the required with the given
absolute lies not so much in the carelessness of the individual as in the
nature of our cognitive faculty. The Ideas carry with them an unavoidable
illusion of objective reality, and the sophistical inferences which spring
from them are not sophistications of men, but of pure reason itself, are
natural misunderstandings from which even the wisest cannot free himself.
At best we can succeed in avoiding the error, not in doing away with the
transcendental illusion from which it proceeds. We can see through the
illusion and avoid the erroneous conclusions built upon it, not shake off
the illusion itself.

On this erroneous objective use of the Ideas three so-called sciences are
based: speculative psychology, speculative cosmology, and speculative
theology, which, together with ontology, constitute the stately structure
of the (Wolffi