What is science (4). Doubt
René Descartes (1596–1650) was a French philosopher who is widely regarded as thefather of modern philosophy. He is also known as a great mathematician and the father of Analytic Geometry. Young Descartes in 1918 joined the International College of War of Maurice of Nassau in the Dutch Republic. In November 1620 was present at the Battle of the White Mountain outside Prague. On the night of 10–11 November 1619, Descartes experienced a series of visions which he later claimed as the reason to become a scientist. Three years later he decided to sell all of his property and invest in bonds which provided him with a comfortable income for the rest of his life. He worked on providing a philosophical framework for the natural sciences as these began to develop. In 1637 he published the Discourse on the Method attempting to arrive at a fundamental set of principles that one can know as true without any doubt.
Descartes defines knowledge in terms of doubt, which was an epistemological innovation. He conceives of knowledge as advancing truth, from unshakable first principles. Science is conceived as organized knowledge in the manner of a well-structured, architectural edifice which owes its structural integrity to two kinds of features: a firm foundation and a superstructure of support beams firmly anchored to the foundation. This knowledge organization is inspired by Euclid’s Geometry;
“Those long chains composed of very simple and easy reasoning, which geometers customarily use to arrive at their most difficult demonstrations, had given me occasion to suppose that all the things which can fall under human knowledge are interconnected in the same way.”
In order to start to build this structure we should examine those things which we think to be true and reject all those beliefs of which there might be some doubt¹ (which can be a very long -possibly impossible- process). In order to be more effective Descartes proposes to group beliefs by focusing on the faculty, such as the senses, the imagination or reason, from which beliefs are derived. Then he proposes to deploy a series of skeptical hypotheses which call into question the knowledge derived from these faculties.
In his work Meditationes de prima Philosophia² in 1641 he described this method (The method of doubt) which is an extended exercise in learning to doubt about everything, considered at three distinct levels:
1. Perceptual Illusion; the testimony of the senses with respect to any particular judgment about the external world may turn out to be mistaken.
2. The Dream Problem; it is possible that everything I now “perceive” to be part of the physical world outside me is in fact nothing more than a fanciful fabrication of my own imagination.
3. A Deceiving God; whenever I believe anything, even if it has always been true up until now, a truly omnipotent deceiver could at that very moment choose to change the world so as to render my belief false.
¹ Here Descartes tried to defeat skepticism on its own ground; He begin by doubting the truth of everything, not only the evidence of the senses. This is a very difficult work but he hopes that if any particular truth about the world can survive this extreme skeptical challenge, then it must be truly indubitable.
² Some believe that the purpose of the method of doubt was to offer to contemporary theologians his proofs of the existence of god and the immortality of the human soul. Others believe that even if Descartes did that, he did it because he hoped to preserve a distinct arena for the church while securing the freedom of scientists to develop mechanistic accounts of physical phenomena.