Theological Origins of Modernity

descartes’ path to truth 197
can only be recognized as true when it is performed or experienced. Or to
put the matter in Kantian terms, it is a synthetic a priori truth. Th at said,
it is not just any synthetic a priori truth; it is rather the I’s self-grounding
act, its self-creation. Descartes explains the nature of such self-grounding
judgments in the Replies: “We cannot doubt them unless we think of them,
but we cannot think of them without at the same time believing that they
are true. . . . Hence we cannot doubt them without at the same time believing
they are true, that is, we can never doubt them.” 109 In order to understand
the nature of this conclusion, however, we need to examine more
fully what Descartes means by thinking and judging.
Descartes defi nes thinking in a variety of ways. In the Rules he lists four
cognitive capacities: understanding, imagination, sensation, and memory.
110 In his later thought he expands his notion. In the Second Meditation
he asserts that a thing that thinks is a thing that doubts, understands, affi
rms, denies, wills, refuses, imagines, and senses. 111 In the Th ird Meditation
he characterizes himself as a thinking thing (res cogitans) who doubts,
affi rms, denies, knows a few things, is ignorant of many, loves, hates, wills,
desires, and also imagines and senses. 112 In the Replies he asserts that
thought includes everything we are immediately conscious of and falls into
four general categories, will (which includes doubt, affi rmation, denial, rejection,
love, and hate), understanding, imagination, and sensation. 113 In
the Principles, he argues that thinking is divided into two modes: (1) perception
or the operation of the intellect which includes sensation, imagination,
and the conception of things purely intellectual, and (2) action of
the will that includes desiring, holding in aversion, affi rming, denying, and
doubting. 114 Finally, in the Passions he argues similarly that there are two
basic functions of the soul, its actions and its passions. 115 Only those passions
that originate in the body are in his view passions properly speaking;
those that arise in the soul are both actions and passions and take their
name from the nobler former capacity.
We saw earlier that judgment for the early Descartes was made possible
by the power of the imagination that brought together the schematized images
derived from sensation with formalized ideas. In his later thought, the
imagination becomes more a screen on which the images are projected, the
backside of the brain or pineal gland. 116 In this sense it is no longer the active
power in judgment. For the mature Descartes, judgment is the combination
of two diff erent mental capacities, will and understanding. Th e latter
is more passive than before, and the role of will much greater. Th rough
will, for example, the understanding becomes active as perception (from
percipere, literally “by grasping”). Will stimulates the brain to form images