"By nature, knowledge depends on a certain similarity between the knower and the known. The old axiom is that like is known by like. In the matters of the mind and where persons are concerned, this means that knowledge calls for a certain degree of empathy, by which we enter, so to speak, into the person or intellectual reality concerned, become one with him or it, and thus become able to understand (intellegere = ab intus legere).
We can illustrate this with a couple of examples. Philosophy can only be acquired if we philosophize, if we carry through the process of philosophical thought; mathematics can only be appropriated if we think mathematically; medicine can only be learned in the practice of healing, never merely by means of books and reflection. Similarly, religion can only be understood through religion--an undisputed axiom in more recent philosophy of religion. The fundamnetal act of religion is prayer, which in the Christian religion acquires a very specific character: it is the act of self-surrender by which we enter into the Body of Christ. Thus it is an act of love.
[As was demonstrated in the previous section of this book...] prayer was the central act of the person of Jesus and, indeed, that this person is constituted by the act of prayer, of unbroken communication with the one he calls 'Father'. If this is the case, it is only possible really to understand this person by entering into this act of prayer, by participating in it. This is suggested by Jesus' saying that no one can come to him unless the Father draws him (Jn 6:44). Where there is no Father, there is no Son. Where there is no relationship with God, there can be no understanding of him who, in his innermost self, is nothing but relationship with God, the Father--although one can doubtless establish plenty of details about him. Therefore a participation in the mind of Jesus, i.e., in his prayer, which (as we have seen) is an act of love, of self-giving and self-expropriation to men, is not some kind of pious supplement to reading the Gospels, adding nothing to knowledge of him or even being an obstacle to the rigorous purity of critical knowing. On the contrary, it is the basic precondition if real understanding, in the sense of modern hermeneutics--i.e., the entering-in to the same time and the same meaning--is to take place.