"RULES FOR THE DIRECTION OF
OUR INTELLIGENCE."
PREFATORY NOTE.
This seems to be the earliest of Descartes' philosophical works. The editors of the latest French edition of his works assign it to the year 1628 (Œuvres, edit. Adam et Tannery, Vol. x. pp. 486 sqq.), just before his removal to Holland and nine years after the idea of a new Method in philosophy first occurred to him.
The work was to have been complete in thirty-six rules falling into three parts containing twelve rules each. The first part gives the general nature of Descartes' new Method; while in the second a transition is made to its application in the field of Mathematics. Unfortunately the treatise, which was never completed, breaks off after, Rule XXI, and indeed the explanation of the last three rules is also omitted. The third part was to have shown the application of the Method to the general problems of Philosophy.
The treatise was not published during the author's lifetime and appeared first in print in the Opuscula Posthuma published at Amsterdam in 1701. The original MS. had passed to Clerselier and was employed by Arnauld and Nicole, the authors of the Port Royal Logic, in their second edition of that work, which appeared in 1664. It appears now to be irrevocably lost. The Amsterdam edition seems to have been made from a copy left in Holland, and M. Adam has been able to collate the text with another copy (not in Descartes' handwriting) which Leibniz secured in Holland in 1670 and which still remains in the Royal Public Library of Hanover.
Much of the doctrine contained in this work will be afterwards met with in the "Method," "Meditations," etc., but there are important points in which there is a discrepancy between the earlier and later writings. More noteworthy still is the fact that there are several speculative suggestions (e.g. certain of those about 'simple natures') which never received further development in Descartes' philosophy.
For further information about our author's mathematical doctrine the reader is referred to his Géometrie, etc.
