Routledge History of Philosophy Volume IV

DESCARTES: METAPHYSICS AND THE PHILOSOPHY OF MIND 205
Descartes’s own views about sensory experience are in fact rather different.
Descartes does not say that sensations are mental events simpliciter; on the
contrary, he explicitly says that ‘I could clearly and distinctly understand the
complete “me” without the faculty of sensation’. 93 Sensation, though it is an
inescapable part of my daily experience, does not form an essential part of the
res cogitans that is ‘me’. Rather, Descartes explains, it is a ‘confused’ mode of
awareness which ‘arises from the union and as it were intermingling of the mind
with the body’. 94
It emerges from this that Descartes’s universe is not quite as neat and tidy as
the label ‘Cartesian dualism’ tends to suggest. It is true that there exist, for
Descartes, examples of pure thinking things—angels are his standard example—
whose existence consists essentially and entirely in modifications of intellection
and volition; such beings are examples of a res cogitans in the strict sense. On
the other side of the divide, there is pure res extensa, mere extended matter
whose every feature can be analysed as some kind of modification of the
geometrically defined properties of size and shape; 95 the human body is an
example of a structure, or assemblage of structures, composed entirely of
extended matter. But human beings fit into neither of the two categories so far
described. For a human being consists of a mind or soul ‘united’ or
‘intermingled’ with a body; and when such intermingling occurs, there ‘arise’
further events, such as sensations, which could not be found in minds alone or in
bodies alone.
Although the ‘union’ between body and soul is explicitly mentioned in the
Meditations, the concept is left somewhat obscure, and it was not until he was
questioned in detail by Princess Elizabeth of Bohemia that Descartes came to
examine in more detail exactly what it implied. We have, he wrote in a letter to
the Princess of 21 May 1643, various ‘primitive notions’ which are ‘models on
which all our other knowledge is patterned’. He proceeds to list some of the
categories which he had much earlier labelled as ‘simple natures’: first, there are
‘common’ notions, such as being, number and duration, ‘which apply to
everything we can conceive’; second, there is the corporeal notion of extension,
‘which entails the notions of shape and motion’; and third, there is the ‘notion of
thought, which includes the conceptions of the intellect and the inclinations of
the will’. All this is straightforward Cartesian doctrine. But now Descartes adds a
fourth category: ‘as regards soul and body together, we have the notion of their
union, on which depends our notion of the soul’s power to move the body, and
the body’s power to act on the soul and cause sensations and passions’. 96 He
later made it clear that the notion of a ‘union’ was meant to be taken literally:
to conceive the union between two things is to conceive them as one single
thing…. Everyone invariably experiences the union within himself without
philosophizing. Everyone feels that he is a single person [une seule
personne] with thought and body so related by nature that the thought can
move the body and feel the things that happen to it. 97