Dear Dr. Schwarz, 2 March 1954
The concept of finality seems to me a logical complement of causality, and I therefore think that only the two aspects make up the sum total of causality.
Just as the connection between cause and effect is a necessity, so is the connection of the so-called final cause with the result.
Without necessity there is neither causality nor finality, although there are not a few people nowadays who treat the concept of causality very incautiously.
Finality shows itself in the teleological character of biological phenomena; but I would not know where finality could be pointed out in the realm of the inorganic.
The 4 aspects of causality make possible a homogeneous causal viewpoint but not a total one.
For this purpose, it seems to me, causality (in all its aspects) has to be complemented by acausality.
Not simply because freedom also is guaranteed in a law-bound world, but because freedom, i .e., acausality, does in fact exist.
In order to express such a proposition, however, one must have a "rigorous" concept of causality, using the term "causality" only when it is really a matter of necessary connections, and "acausality" only when a causal connection is not even thinkable, e.g., in hysteronproteron, where an event in the present appears to be caused by a future event.
As for your question about faith, I must emphasize that there are apparently two realities: objective and subjective, by reason of the fact that objective reality can be established as being nonpsychic, whereas psychic reality cannot be established as being objective in the same sense.
But this is due primarily to the unavoidable premise that perception and judgment are themselves psychic, and that Consequently one cannot jump over one's own head.
Nevertheless, the reality of the psyche can be established by means of verified statements or objectively verifiable symptoms.
Hoping I have answered your questions,
C.G. Jung ~Carl Jung, Letters Vol. II, Pages 157-158.