There is a different concept of knowledge when applied to knowing a person, by contrast to knowledge as used in the natural sciences. We are dealing here with the fundamental difference between the Hebrew and the Greek ideas of knowledge. In the Hebrew concept, „to know“ (jada) was essentially the active experience of a person, a concrete and personal relationship rather than an abstraction. (…) „To know“ in the Hebrew sense also means both penetrating sexual love and deep understanding.

In the Greek, especially in Aristotle’s works, knowledge of an object is impersonal and objective, and this kind of knowledge has become the basis for the natural sciences. Although the therapist also thinks in these objective terms when he considers many aspects of his patient’s problems, his main approach must be the „knowledge of active experience“; this is the scientific method appropriate for the understanding of persons. ― (1990f [1969]: The Dialectic Revision of Psychoanalysis, in: E. Fromm, The Revision of Psychoanalysis, Boulder (Westview Press) 1992, pp. 20f.)