xa. princess elizabeth to descartes 1 
[On the relation of soul and body]
The Hague, 10-20 June 1643.
. . . <I cannot> understand the idea by means of which we are to judge of the way that the soul, unextended and 1 [Corresp., No. 308;  Oeuvres, A.-T., vol. iii, p. 684.—ed.]
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LETTERS
immaterial, moves the body, in terms of the idea you used to have about gravity. You used falsely to ascribe to gravity, under the style of a 'quality', the power of carrying bodies towards the centre of the Earth. But I cannot see why this should convince us that a body may be impelled by something immaterial; why we should not rather be confirmed in the view that this is impossible, by the demonstration of a true <view of gravity>, opposed <to this>, which you promise us in your Physics; especially as the idea <that a body may be so impelled> cannot claim the same degree of perfection and representative reality (réalité objective) as the idea of God, and may be a figment resulting from ignorance of what really moves bodies towards the centre. Since no material cause was apparent to the senses, people may well have ascribed this to the opposite cause, the immaterial; but I have never been able to conceive that, except as a negation of matter, which can have no communication with matter.
And I must confess that I could more readily allow that the soul has matter and extension than that an immaterial being has the capacity of moving a body and being affected by it. If the first, <the soul's moving the body>, took place by <the soul's giving> information <to the body>, then the <animal> spirits, which carry out the movement, would have to be intelligent; but you do not allow intelligence to anything corporeal. You do indeed show the possibility of the second thing <the body's affecting the soul>, in your Metaphysical Meditations; but it is very hard to see how a soul such as you describe, after possessing the power and the habit of correct reasoning, may lose all that because of some vapours <in the brain>; or why the soul is so much governed by the body, when it can subsist separately, and has nothing in common with it. ...
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