DES CARTES. 
in the church of St. Genevieve. Such was 
the life of this great man : his writings and 
system require a more detailed account. 
On the subject of logic, he says, nothing 
is ever to be admitted as true, which is not 
certainly and evidently known to be so, and 
which cannot be possibly doubted. In 
proving any truth, the ideas are always to 
be brought forward in a certain order, be- 
ginning from things the most simple, and 
advancing by regular steps to those which 
are more complex and diflScult. With re- 
gard to metaphysics, Des Cartes says, that 
since man is under the influence of preju- 
dice, he ought, once in his life, to doubt 
of everything; even whether sensible ob- 
jects have a real existence ; and also of the 
truth of mathematical axioms. The first 
principle of the Cartesian philosophy is this, 
“ I THINK, THEREFORE 1 AM this is the 
foundation of Des Cartes’s metaphysics : 
that on which his physics is built, is, “ That 
NOTHING exists BUT SUBSTANCES.” Sub- 
stance he makes of two kinds ; the one that 
thinks, the other is extended : so that ac- 
tual thought and actual extension make the 
essence of substance. The essence of mat- 
ter being thus fixed in extension, Des 
Cartes concludes that tliere is no vacuum, 
nor any possibility of it in nature, but that 
the universe is absolutely full; by this 
principle, mere space is quite excluded; 
for extension being implied in the idea of 
space, matter is so too. 
Des Cartes defines motion to be the 
translation of a body from the neighbour- 
hood of others that are in contact with it, 
and considered as at rest, to the neighbour- 
hood of other bodies: by which he destroys 
the distinction between motion that is ab- 
solute or real, and that which is relative or 
apparent. He maintains that tlie same 
quantity of motion is always preserved in 
the universe, because God must be sup- 
posed to act in the most constant and im- 
mutable manner: and hence also he de- 
duces his three laws of motion. 
Upon these principles Des Cartes ex- 
plains mechanically how the world was 
formed, and how the present phenomena of 
nature came to arise. He supposes that 
God created matter of an indefinite exten- 
sion, which he separated into small square 
portions or masses, full of angles : that he 
impressed two motions on this matter; the 
one, by which each part revolved about its 
oWh centre ; and another, by which an as- 
semblage or system of them turned round 
a common centre. From whence arose as 
many different vortices, or eddies, as there 
were different masses of matter, thus mov- ' 
ing about common centres. 
The consequence of these motions in 
each vortex, according to Des Cartes, is as 
follows : the parts of matter could not thus 
move and revolve amongst one another, 
without having their angles gradually 
broken ; and this continual friction of parts 
and angles must produce three elements : 
the first of these, an infinitely fine dust, 
foi-med of the angles broken off ; the se- 
cond, the spheres remaining, after all the 
angular parts are thus removed ; and tliose 
particles not yet rendered smooth and sphe- 
rical, but still retaining some of their angles, 
and hamous parts, from the third element. 
Now the first or snbtilest element, ac- 
cording to the laws of motion, must occupy 
the centre of each system, or vortex, by 
reason of the smallness of its parts: and 
this is the matter which constitutes the sun, 
and the fixed stars above, and the fire be- 
low. The second element, made up of 
spheres, forms the atmosphere, and all the 
matter between the earth and the fixed 
stars ; in sueh sort, that the largest spheres 
are always next the circumference of the 
vortex, and the smallest next its centre. 
The third element, formed of the irregular 
particles, is the matter that composes the 
earth, and all terrestrial bodies, together 
with comets, spots in the sun, &c. 
He accounts for the gravity of terrestrial 
bodies from the centrifugal force of the 
ether revolving round the earth : and upon 
the same general principles he pretends to 
explain the phenomena of the magnet, and 
to account for all the other operations in na- 
ture. 
Of this great man many eulogia have 
been published, by persons very capable 
of appreciating his worth and his talents. 
We shall mention the opinion entertained 
of him by two or three of our own coun- 
trymen. 
Dr. Barrow, in his “Opuscula,” ob- 
serves, that Des Cartes was doubtless a 
very ingenious man, and a real philosopher, 
and one who seems to have brought those 
assistances to that part of philosophy re- 
lating to matter and motion, which perhaps 
no one had done before ; namely, a great 
skill in mathematics; a mind habituated, 
both by nature and custom, to profound 
meditation; a judgment exempt from all 
prejudices and popular eiTors, and furnish- 
ed with a good number of certain and se. 
lect experiments ; a great deal of leisure ; 
