With this new synthesis of a priori meaning added to the concept
of Space, we then find that the previous errors and contradictions (paradoxes)
simply disappear. Now this is a profound solution, for this error of Matter
'particles' moving about in Space and Time has now existed for 2,500 years,
and has detrimentally influence such great minds as Schopenhauer, Nietzsche,
Mach, and Einstein, and has ultimately led to our current Postmodern Idealism
See the complete article Immanuel Kant which explains and solves Kant's Metaphysics.
Note that Descartes is not seeking to root out merely unjustified believes -- but rather unjustifiable beliefs. Because it must be logically possible for a justifiable proposition to be false, not only true -- and therefore no such proposition can be absolutely certain (" the bedrock or the clay"). And it is absolute certainty that Descartes seeks, not merely more-or-less justified belief. It is not logically possible for "I think, therefore I exist" to be false. And Descartes is not concerned with what "we" know, but only with what he himself knows; because he can doubt that anyone but he himself exists. Descartes' project begins with "know thyself" -- . self-knowledge.