Descartes’ moral rules demonstrate both his distrust of
the material world and his confidence in his mind’s ability to overcome
it. He has near-absolute faith in his ability to control his own
mind and believes that he only needs to change it to change reality.
If he wants something he can’t have, he won’t struggle to get it
or be miserable about not having it. Instead, he’ll just decide
not to want it. Descartes’ resolution to become a spectator rather
than an actor in the events of the world around him amounts almost
to a renunciation of his physical existence. Long after Descartes,
scientific study was governed by the ideal of detached observation
advanced by Descartes.
Part Four of Discourse is a precursor
to his later work, Meditations on First Philosophy, and
the major ideas he provides here—that the self exists because it
thinks and that God exists because the self is imperfect and there
must be a source for the idea of perfection outside the self—are
mere sketches of the detailed explanation he provides in Meditations.