‘SELECTIONS FROM THE PRINCIPLES OF PHILOSOPHY’ by DESCARTES begins by according philosophy, high status, as the science of wisdom. The book also says, “in order to seek truth, it is necessary once in the course of our life, to doubt, as far as possible, all things.” The author divides the whole work into four parts, the first of which contains the principles of human knowledge, and which may be called the First Philosophy, or Metaphysics. The other three parts contain all that is most general in Physics, namely, the explication of the first laws or principles of nature, and the way in which the heavens, the fixed stars, the planets, comets, and generally the whole universe, were composed; in the next place, the explication, in particular, of the nature of this earth, the air, water, fire, the magnet, which are the bodies we most commonly find everywhere around it, and of all the qualities we observe in these bodies, as light, heat, gravity, and the like.
The complete book is in fact made up of about 207 independent paragraphs, each dealing with one specific question. Like “Why we may also doubt of mathematical demonstrations?”, What thought (COGITATIO) is, and why, I think, is superior to other expressions like, I see, or, I walk. Who can fail to notice the beauty in his reasoning? For example, see his treatment of errors, “The chief cause of our errors is to be found in the prejudices of our childhood. The second cause of our errors is that we cannot forget these prejudices. The third cause is, that we become fatigued by attending to those objects which are not present to the senses; and that we are thus accustomed to judge of these not from present perception but from pre-conceived opinion. The fourth source of our errors is, that we attach our thoughts to words which do not express them with accuracy”, or his assessment of the material world, where he says, “the perceptions of the senses do not teach us what is in reality in things, but what is beneficial or hurtful to the composite whole of mind and body”. I found the ideas quite illuminating, and the book as a whole, an excellent read. The book ended with another declaration that the author “desires no one to believe anything that may have been said, unless he is constrained to admit it by the force and evidence of reason”.