17. Metaphysics itself happens to be interested, albeit somewhat indirectly, in such a practical philosophy. For man is part of the universe, and the world of human action is intrinsically linked to the great universe of creation. Besides, if reason left all to itself is able to stammer some very general and indefinite truths concerning the problems of evil and of divine governance, for example, it is impotent to deal with them adequately without taking into account the existential conditions in which such problems are embodied. And hence it must also take into consideration the de facto state in which human life is established (in itself and in its relations with the universe), its finalities not merely possible but really given, and therefore a host of other matters which depend on superior lights.

It should be added that even independently of this link with practical philosophy there exist many problems which metaphysics simply, as a speculative science poses but does not resolve, or resolves incompletely, and whose solution is provided by faith yet grasped in all its truth and its fitness only in the light of infused contemplation. . . . Like any human science metaphysics leaves us unsatisfied. Being turned toward the First Cause, and harboring a natural desire for knowing It perfectly, it is only natural that it should awaken in us a desire -- inefficacious and conditional but real -- to see this Cause in itself, to contemplate God's essence. It can never fulfil this desire."^{23} So there is, as Mr. Blondel has justly observed, a void or an incompleteness of which every discerning metaphysic must necessarily become aware, and which without in any wise anticipating the nature of the answer, will find at one and the same time better fulfilment and further deepening (and this in an ever-increasing measure until God is seen face to face) in the Christian answer. But here again, owing to its state in the human soul, philosophy has need of objective illumining and of the succor of faith to attain full self-realization. Even if we are able to say that in virtue of the above-mentioned desire the true metaphysics is naturaliter christiana, it will as a matter of fact meet with as much difficulty in disclosing this desire in its pure form and in arriving at an exact awareness of this void as in gaining the flawless possession of the loftiest truths of reason. It is by being effectively Christian in the sense which I have tried to make clear above that it will reach this twofold objective.

{23} Les Degrés du Savoir, p. 562.