Cartesian

American Heritage® Dictionary of the English Language, Fourth Edition

1. adj. Of or relating to the philosophy or methods of Descartes.

Century Dictionary and Cyclopedia

1. Pertaining to the French philosopher René Descartes (1596-1650), to his philosophy, or to his geometrical method. In order to put philosophy on a sound basis, Descartes professed to begin by doubting all things. But the doubt, the thought, could not be doubted; hence the fundamental proposition of his philosophy, Cogito, ergo sum (I think, therefore I am). This proposition (which is not a syllogism nor any formal mode of inference) means that, recognizing the fact that I think, I am irresistibly led to believe and clearly to discern that I exist, without being able to account for the inference. According to Descartes, the consideration that the conception of a deity involves the conception of a reality surpassing my own leads to the irresistible belief and clear perception of the existence of a God. Also, since veracity is an attribute of God, all that is clearly and distinctly apprehended must be true. This is the so-called Cartesian criterion of truth. Substances, he taught, are of two radically different kinds: the material, which are extended and not conscious, and the spiritual, which are conscious and not extended—a doctrine which is called Cartesian dualism. The Cartesian doctrine of divine assistance, or occasionalism, which was not fully developed by Descartes himself, is that whenever the soul makes a volition God intervenes to cause the corresponding motion of the body. He also taught that brutes are mere machines without consciousness (the Cartesian automatism.), and that all space is filled with matter, which turns about in vortices, and so produces the motions of the heavenly bodies.
2. n. One who adopts the philosophy of Descartes; a follower of Descartes.
3. n. Any curve of the fourth order having two cusps on the absolute. There are three genera of Cartesians. The first consists of curves of the sixth class, composed of a pair of Cartesian ovals, one inside the other. The second genus consists of curves of the fourth class, which are limaçons. Curves of this kind generally have an acnode which may become a crunode. The third genus consists of the cardioid, which is a curve of the third class with and a real cusp. Every Cartesian has a single bitangent.

Wiktionary

1. adj. Of, or pertaining to, Descartes, his mathematical methods, or his philosophy, especially with regard to its emphasis on logical analysis and its mechanistic interpretation of physical nature.
2. adj. mathematics, cartography Of, or pertaining to, co-ordinates based on mutually orthogonal axes.
3. n. One who follows the philosophy of Cartesianism.

GNU Webster's 1913

1. adj. Of or pertaining to the French philosopher René Descartes, or his philosophy.
2. n. An adherent of Descartes.

WordNet 3.0

1. adj. of or relating to Rene Descartes or his works
2. n. a follower of Cartesian thought