In this paper, I will deal with two problems in order to clarify the meaning
of first philosophy in Descartes' thinking. Firstly, I will attempt to show that
the ontological or onth-theo-logical interpretation of Descartes' first philosophy
by Martin Heidegger and Jean-Luc Marion is not legitimate. According to this
reading, the generality of Descartes' first philosophy means that of Being which
could apply to every thing in the same way. But, on the contrary to this
interpretation, the author of Meditationes de prima philosophia neither seeks a
general sens of being in totality nor builds an ontological or metaphysical
system for explaining every being. Secondly, I will attempt to illuminate that in
Descartes' thinking, first philosophy is not reducible to metaphysic. The
investigation of these two problems could make clear that Descartes's first
philosophy provides foundations for his philosophical project of universal
science, which consists in elevating our nature to the highest degree of
perfection.