ABSTRACT
It is evident that the Fifth Meditation is expounding the possibility of a science of nature that is in a sense a priori. Descartes has not yet accorded any truth to the deliverances of sense experience, and has not yet affirmed the existence of any corporeal entity. Further, the innumerable particulars of figure, motion, etc., concerning which he now claims certain knowledge are said to have been already present to his mind, or ‘drawn from it.’ It is a question, then, of the innate science described in Part V of the Discourse:
I have…observed certain laws which God has so established in nature and of which He has imprinted such notions in our minds, that, after having reflected sufficiently on the matter,6 we cannot doubt that they are exactly observed in all that exists or that occurs in the world. Further, in considering the consequences of these laws, it seems to me that I have discovered a number of truths more useful and more important than all that I had formerly learned or even hoped to learn…. [In the treatise on the World] I described…matter and tried to represent it in such a way, that it seems to me that there is nothing in the world more clear and intelligible, excepting what has just been said of God and the soul: for I even supposed expressly that there was in it none of these forms or qualities which are debated in the Schools, nor generally anything the knowledge of which is not so natural to our souls that one could not even pretend to be ignorant of it. Further, I explained what are the Laws of Nature, and, without resting my reasons on any other principle than the infinite perfections of God, I tried to demonstrate all those of which one could have any doubt…. (AT VI, 413; HR I, 106-8)
But while the science of Meditation V is in this sense a priori, it does not follow that it is strictly a science of pure intellect, or of mind in separation from body. Very significantly, Descartes begins his exposition with the following words:
I distinctly imagine the quantity which philosophers commonly call continuous, or the extension of this quantity…in length, breadth, or depth….
