c CUNYB/Clarke December, :
The Quarrel and Final Rift with Regius not have enough knowledge...to speak in the same way as about the rest’
(vi.). However, the lack of specific knowledge did not prevent Descartes
from speculating, in great detail, about how the human brain works both
in receiving information from outside and in causing the body to react
appropriately in response to its perceptions.Then I had shown...what the structure of the nerves and muscles of the human
body would have to be in order for the animal spirits in the body to have the power
to move its members...what changes must be made in the brain to cause waking,
sleep, and dreams; how light, sounds, odours, tastes, warmth and all the other qualities
of external objects can impress different ideas [id ́ees]onitthrough the senses; how
hunger, thirst, and the other internal passions can also send their ideas there; what
part of the brain should be taken as the ‘common sense’ where these ideas are received;
what should be taken as the memory, which stores the ideas, and as the imagination,
which can vary them in different ways and compose new ones and, by the same means,
distribute the animal spirits to the muscles and cause the limbs of the body to move in
as many different ways as our own bodies can move without the will directing them,
depending on the objects that are present to the senses and the internal passions of
the body. (vi.)This would not surprise those who know anything about automata, he
thought. Without any explicit reference to the work of De Caus he
surmised: if human engineers can construct automata that move like ani-
mals or sing like birds, then surely a body made by God would be ‘incom-
parably better structured’ (vi.), and one could anticipate explaining all
the phenomena about human beings that were mentioned in the passage
just quoted by a sufficiently advanced anatomy and physiology.
This is precisely the line of development that caught the attention of
Regius and, when pushed to its apparent conclusion, would suggest that
souls are redundant even in the case of human beings. TheDiscoursetried
to block that conclusion, however, by offering two arguments to show
that human beings are so different from other animals that they must
have a soul or mind. One argument relied on the distinctive character
of human language. One could easily imagine a machine that uttered
wordsorphrases in response to specific stimuli. However, according to
Descartes, a machine ‘could not arrange words in different ways to reply
to the meaning of everything that is said in its presence, as even the most
unintelligent human beings can do’ (vi.–). The other reason was that,
although machines may perform specific tasks better than we do – such as
clocks telling the time – they always do so in a way that is determined in