Descartes: A Biography

C CUNYB/Clarke     December, :

 Descartes: A Biography

William Harvey ’s book,An Anatomical Exercise concerning the Motion of the

Heart and Blood in Animals, had been published four years earlier and had

been known in France since, when Descartes had left for the United

Provinces. Descartes was among the first to support Harvey’s theory that

the blood circulates continuously through the body and that the pumping

action of the heart is its cause. While Descartes agreed about the main

point – that the blood circulates through the body – he could not accept

Harvey’s apparently mysterious explanation of why the heart beats, which

assumed in the heart a faculty for beating, and he subsequently suggested

an alternative mechanical explanation.

The real significance of his letter to Mersenne, however, is not

Descartes’ agreement or otherwise with Harvey, but the extrapolation

of the scientific project ofThe Worldto include human beings. What was

envisaged was nothing short of a comprehensive explanation, or explana-

tory sketch, of all natural phenomena, including human beings. Even when

the project had been concerned only with astronomy, in May of that year,

Descartes had conceded that the project ‘exceeds the scope of the human

mind’ (i.). The extended scope ofThe Worldnow made its limita-

tions much more obvious. He would discover, in time, that any attempt to

explain human beings went far beyond not only the ability of the human

mind, but also the limits of what ecclesiastical authorities were willing to

tolerate.

There were already indications of possible problems with church

authorities in summer.Jean-Baptiste Morin (–), an estab-

lished professor of mathematics at Paris, had published a book to sup-

port the theory that the Earth is stationary, under the title:The Preferred

Solution, to date, of the Famous and Ancient Problem of the Motion or Non-

motion of the Earth(). He argued that the hypothesis of the Earth’s

motion was not new, and that scripture, astronomy, and physics all sup-

ported the conclusion that the Earth is stationary.‘The Sacred Scrip-

tures show that it is far more certain and evident that the earth is stationary

rather than in motion.’Having outlined the scriptural reasons – sum-

marized in the quotation from Ecclesiastes (:)onthe title page: ‘The

earth stands firm forever. The Sun rises, the Sun sets’ – Morin borrows

reasons from astrology to show that ‘the earth is the receptacle or the

passive subject of all the celestial influences’ and is therefore stationary at

the centre of the universe.Descartes’ comment on this was completely

dismissive: ‘I feel sorry, as you do, for the author who uses astrological