In every philosophical school, three thinkers succeed one another in the following way: the first produces out of himself the sapand seed, the second draws it out into threads and spins a synthetic web, and the third waits in this web for the sacrificial victims that are caught in it--and tries to live off philosophy.
A philosophy can and must be worked out with the greatest rigour and discipline in the details, but can ultimately be founded on nothing but faith: and this is the reason, I suspect, why the novelties in philosophy are only in elaboration, and never in fundamentals.