by: Rene Descartes, read in 2020

xx "Descartes ...devised a radical new theory of the nature of matter, defined simply as extension in three dimensions, and formulated a number of mathematical laws describing the results of collisions of moving particles of matter."
xxiv "The upshot of this night of troubled visions was that Descartes became convinced that his own life's journey should be devoted to completing the 'encyclopaedia': his mission was to found a new and comprehensive philosophical and scientific system." Sounds familiar.
28 "I am a thing that thinks: that is, a thing that doubts, affirms, denies, understands a few things, is ignorant of many things, is willing, is unwilling, and also which imagines and has sensory perceptions; "
29 "[W]hatever I perceive very clearly and distinctly is true." The French version substitutes 'conceive' in place of 'perceive' which I think is better. In either case, I think the role of language is important in this context. A distinction should be made between sentences and propositions, and truth should be attributed only to propositions.
33 "What is more perfect-that is, contains in itself more reality-cannot arise from what is less perfect. " That is a connotation of 'perfect' that I can accept.
34 "So it is clear to me, by the natural light, that the ideas in me are like images which can easily fall short of the perfection of the things from which they are taken, but which cannot contain anything greater or more perfect." I disagree. Is there more or less reality, or perfection, in an image of the Mandelbrot Set or in the simple formula? I think in the image. This suggests some diminution of the perfection of God as you go up.
36 "[M]y perception of the infinite is arrived at not by means of a true idea but merely by negating the finite. " Not a convincing basis.
68 "As for the faculties of willing, of understanding, of sensory perception and so on, these cannot be termed parts of the mind, since it is one and the same mind that wills, and understands and has sensory perceptions. By contrast, there is no corporeal or extended thing that I can think of which in my thought I cannot easily divide into parts; and this very fact makes me understand that it is divisible. This one argument would be enough to show me that the mind is completely different from the body, even if I did not already know as much from other considerations.

My next observation is that the mind is not immediately affected by all parts of the body, but only by the brain, or perhaps just one small part of the brain, namely the part which is said to contain the 'common' sense. The supposed faculty which integrates the data from the five specialized senses (the notion goes back ultimately to Aristotle). 'The seat of the common sense must be very mobile, to receive all the impressions which come from the senses; but it must also be of such a kind as to be movable only by the spirits which transmit these impressions. Only the conation [pineal gland] fits this description' (letter to Mersenne, 21 April 1641. " I think the claustrum is a better candidate.
91 "[W]hen you think, you know and consider that you are thinking (and this is really what it is to be conscious and to have conscious awareness of some activity)." Claimed by a critic of Descartes who denies it.
100 "[I]f someone calls something 'infinite' he attributes to a thing which he does not grasp a label which he does not understand." Quoted from a critic of Descartes.
110 "I observe, amongst my other thoughts, that there is within me the idea of a supremely perfect being." It puzzles me how he could be so certain of this.