Founder of a Metaphysics of Morals 327Yet however much it is contrary to the Kantian view to say that objects
make impressions upon our senses, it is impossible to understand how the
Kantian view could even get started without this presupposition.^237
In other words, Kant's categories of the understanding are really qual¬
ities of sensation. Jacobi asked why the "laws of reason" are more neces¬
sary than "laws of sensation." Why are laws of thought "objective," while
laws of sensation are only "subjective"? These questions can be put, ac¬
cording to Jacobi, not only to Kant, but to all rationalists. For, as Jacobi
saw it, the rationalists' affirmation of reason and denigration of the senses
was nothing but a prejudice. He argued that the Kantian system itself
presupposed laws of sensation, and that the categories are faint copies or
shadows of basic principles of sensation. Without presupposing such prin¬
ciples of sensation, the Kantian system would be impossible.
Jacobi went on to argue that a transcendental idealist could not even at¬
tain the conception of an object that is "external to us in a transcendental
sense."^238 The conception of such an object is based upon the "truly won¬
derful revelation of sensation." Only the realist can attain the conception
of such an object, since for him sensation is the passive state of being acted
upon. But this feeling is only "one half of the entire state, a state which
cannot be thought merely in accordance with this one half."^239 It necessarily
involves an object that has caused this state. External sensation necessarily
suggests a really existent external object, and the laws that lead common
sense toward such objects are not laws of thought but laws of sensation.
We must assume that things in themselves affect us. Jacobi claimed that
"without this presupposition I cannot enter into the system, but with this
presupposition I cannot remain within the system."^240 Kant's philosophy
had removed itself too far from sensation and ordinary language. By try¬
ing to "purify" thought of the influence of the suggestions of sensation
and the concepts of thought from the influence of ordinary language, crit¬
ical philosophy becomes nihilism. There is, thus, no such thing as "pure
reason." Reason is always "contaminated" by sensation and ordinary lan¬
guage (just as Hamann had argued in his Metacritique). Thus, any critique
of reason must necessarily involve a critique of the preconditions of rea¬
son, namely a critique of sensation and ordinary language.
Jacobi's rejection of the Kantian "thing in itself" was only a part of this
project, but it was the criticism that ultimately proved most influential.
Herder also weighed in with a book called God, Some Conversations, which
appeared in 1787. In it, Herder tried to rehabilitate Spinoza, and thus to