It will be seen how the two terms of this opposition lend one another support and reinforce one another; it is in the treasury of positive branches of knowledge (and above all of those that biology, economics, or philology are able to release) that the metaphysics of the 'depths' or of the objective 'transcendentals' will find their point of attack; and, inversely, it is in the division between the unknowable depths and the rationality of the knowable that the positivisms will find their justification.