To E . A. Bennet

My dear Bennet,                            22 May 1960

Thank you very much for your kind review of my Aion.

There is only one remark I do not quite understand.

Speaking of the hypothesis of archetypes, you say that there is no scientific proof of them yet.

A scientific hypothesis is never proved absolutely in so far as an improvement is always possible.

The only proof is its applicability.

You yourself attest that the idea of the archetype explains more than any other theory, which proves its applicability.

I wonder therefore which better proof you are envisaging.

When you assume the existence of an instinct of migration you can’t do better than to apply it f.i. to birds

and demonstrate that there are actually birds which migrate.

The archetype points out that there are thought-formations of a parallel or identical nature distributed all

over the world (f.i., holy communion in Europe and Teoqualo in ancient Mexico), and furthermore that they can be

found in individuals who have neverheard of such parallels.

I have given ample evidence of such parallels and therewith have given evidence of the applicability of my


Somebody has to prove now that my idea is not applicable and to show which other viewpoint is more applicable.

I wonder now, how you would proceed in providing evidence for the existence of archetypes other than their


What is better proof of a hypothesis than its applicability?

Or can you show that the idea of “archetype” is a nonsense in itself?

Please enlighten my darkness.

Yours cordially,

C.G. Jung Carl Jung, Letters Vol. II, Pages 558-559.