Gabriel Marcel:

…I am convinced that I can be creative as a philosopher only for so long as my experience still contains unexploited and unchartered zones.  And this explains at last what I said earlier on about experience being like a promised land:  it has to become, as it were, its own beyond, inasmuch as it has to transmute itself and make its own conquest.  After all, the error of empiricism consists only in ignoring the part of invention and even of creative initiative involved in any genuine experience.  It might also be said that its error is to take experience for granted and to ignore its mystery; whereas what is amazing and miraculous is that there should be experience at all.  Does not the deepening of metaphysical knowledge consist essentially in the steps whereby experience, instead of evolving technics, turns inward towards the realization of itself?