Student and Private Teacher 89be misleading: Kant was not necessarily a protege of Knutzen. The great
Knutzen, predictor of the course of comets, was not his mentor, and he did
not support his further career. If Kant did not become a theologian "be¬
cause he was opposed to Pietism," then Knutzen - had he found this out -
would have had grounds for disliking Kant. At the very least, he would have
had grounds for predicting a dim future for Kant in Königsberg.^127 Kant,
on the other hand, must have disliked some of Knutzen's propositions of
"experience." The work he began in 1744 may have been more of a reac¬
tion against Knutzen than one that was positively inspired by Knutzen.
To be sure, the work shows every sign of coming out of the intellectual
milieu fostered by Knutzen. It is more speculative than mathematical,
even if it deals with a question that was still important.^128 Euler's Me¬
chanic a sive motus scientia of 1736 had already moved the question to a dif¬
ferent plane.i29 He had tried — with great success — to formulate and solve
the problems of mechanics-dynamics in a mathematical way. It is not clear
whether Kant, as a student of Knutzen, whose mathematical skills were
hardly up to the task of understanding Euler's Mechanica, knew this work
then. In any case, Kant framed the problem in metaphysical terms, just as
one would expect from anyone who went through this school.
In other ways, the True Estimation of the Living Forces shows — at least in¬
directly — that Kant was on his own. Nothing would prevent him from "tak¬
ing his course." In old age Kant made clear to one of his biographers that
he had tried from his "youth" to be autonomous and independent of every¬
one, so that he "could live for himself and his duty, and not for others. This
independence he declared ... to be the foundation of all happiness."^130
In his first public expression of independence, Kant wrestled with one
of the central disputes in German natural philosophy during the early part
of the eighteenth century, namely the problem of the measurement of
force. Late in the previous century, Leibniz had opposed the Cartesian
theory that matter was completely inert. Leibniz saw Cartesian physics as
an attempt to explain all of nature by what he called "dead force." He dif¬
ferentiated between this "dead force" (vis mortua or conatus) and "living
force" (vis viva). Living force was for him also the force of motion. Dead
force, he thought, did not arise from motion itself but initiated new mo¬
tion and explained changes in motion. This distinction was connected to
the difference between the Cartesian and the Leibnizian account of the
world. Whereas the Cartesians believed that "the nature of body consisted
of inert mass (massa) alone," Leibniz argued that something else needed
to be postulated to account for the phenomena.^131 Saying that he did not