Descartes had four basic rules he used to arrive at the truth?

Answer 1

The following quotation from Discourse on Method presents the four precepts that characterize the Method itself:

The first was never to accept anything for true which I did not clearly know to be such; that is to say, carefully to avoid precipitancy and prejudice, and to comprise nothing more in my judgment than what was presented to my mind so clearly and distinctly as to exclude all ground of doubt.

The second, to divide each of the difficulties under examination into as many parts as possible, and as might be necessary for its adequate solution.

The third, to conduct my thoughts in such order that, by commencing with objects the simplest and easiest to know, I might ascend by little and little, and, as it were, step by step, to the knowledge of the more complex; assigning in thought a certain order even to those objects which in their own nature do not stand in a relation of antecedence and sequence.

And the last, in every case to make enumerations so complete, and reviews so general, that I might be assured that nothing was omitted. By clear and distinct he suggests the evidence of the senses. The enumerations have in time developed into many forms. He suggested drawing boxes on a paper, and connecting them. This idea has led to a multitude of graphic thinking aids that we use today.

References

1. ^ Najm, Sami M. (July-October 1966). "The Place and Function of Doubt in the Philosophies of Descartes and Al-Ghazali". Philosophy East and West(Philosophy East and West, Vol. 16, No. 3/4) 16 (3-4): 133-41. doi:10.2307/1397536
2. ^ Descartes, Rene; Laurence J. Lafleur (trans.) (1960). Discourse on Method and Meditations. New York: The Liberal Arts Press. ISBN 0-672-60278-4.

Answer 2

Descartes' four rules were: 1) Never accept anything as true if there is any doubt; 2) Divide each problem into smaller parts to better solve them; 3) Think clearly and systematically; 4) Review and verify the conclusions reached.