Yes I think philosophy can attain the certainty of mathematics given Rene Descartes’ philosophical system. Descartes' philosophical method was also intended to be a method for science. Characterizing his time is skepticism where doubt was a dominant way of thinking. He used methodic doubt to counter skepticism and is the very core of his philosophy. We might characterize Descartes' general position in the following way: the world created by God was intended by Him to be known, provided only that human beings go about the activity of knowing properly. How the activity of knowing might be properly conducted is the issue of methodology.

Descartes was a mathematician first and foremost. He invented a meta-language –a language patterned after mathematics because he wanted philosophy to be as precise as math. One of the things he realizes is that he can doubt the physical world and the natural sciences and pass them off as hallucination BUT not mathematics. Descartes pursues what he calls a clear and distinct idea, that which is FREE of doubt. Cannot be doubted. What is mathematics? For one mathematics is ANALYTIC. We do not look in the physical world and find the numbers 1+1=2. Rather, analytic forms of knowledge such as mathematics are deduced or reduced through reason. Mathematical statements are conceptual truths.

Back to Descartes, using his methodic doubt, he finds that one thing is clear. That he is doubting and the more he doubts the more he asserts his existence. This is the famous cogito ergo sum. Descartes also advances proof for the existence of God. He begins with the statement that he has an innate idea of God as a perfect being and then intuits that God necessarily exists, because, if he did not, he would not be perfect. This ontological proof for the existence of God is at the heart of Descartes’ rationalism, for it establishes certain knowledge about an existing thing solely on the basis of reasoning from innate ideas, with no help from sensory experience. Descartes then argues that, because God is perfect, he does not deceive human beings; therefore the world exists. Thus Descartes claims to have given metaphysical foundations for the existence of his own mind, of God, and of the world.

As we can see here his system is very much like mathematics. Unlike Aquinas’ proofs for God’s existence (look at the physical world and deduce that God exists), Descartes started from doubt and through reasoning he proved the existence of himself, God, and the physical world. His idea of God is innate (self-evident truth/ clear and distinct idea). For him God exists in an ANALYTIC way. His way of reasoning, his method and conceptualization is very like mathematics. This shows that philosophy can be just as precise as mathematics. After all we don’t call Descartes a rationalist for nothing.