In August 1957, Jung gave a series of filmed interviews for the University of Houston. The following is part of the transcript of the fourth interview with Dr. Richard I. Evans:

I got more and more respectful of archetypes, and now, by Jove, that thing should be taken into account. That is an enormous factor, very important for our further development and for our well-being. It was, of course, difficult to know where to begin, because it is such an enormously extended field. So the next question I asked myself was, “Now where in the world has anybody been busy with that problem?” And I found nobody had, except a peculiar spiritual movement that went together with the beginnings of Christianity, namely Gnosticism. That was the first thing, actually, that I saw, that the Gnostics were concerned with the problem of archetypes. They made a peculiar philosophy of it, as everybody makes a peculiar philosophy of it when he comes across it naïvely and doesn’t know that the archetypes are structural elements of the unconscious psyche.

The Gnostics lived in the first, second, and third centuries. And what was in between? Nothing. And now, today, we suddenly fall into that hole and are confronted with the problems of the collective unconscious which were the same then two thousand years ago – and we are not prepared to meet that problem. I was always looking for something in between, you know, something that linked that remote past with the present moment. And I found to my amazement it was alchemy, which is understood to be a history of chemistry. It is, one might almost say, anything but that. It is a peculiar spiritual or philosophical movement. The alchemists called themselves philosophers, like the Gnostics. And then I read the whole accessible literature, Latin and Greek. I studied it because it was enormously interesting. It is the mental work of seventeen hundred years, in which is stored up all they could make out about the nature of the archetypes, in a peculiar way, that’s true – it is not simple. Most of the texts haven’t been published since the Middle Ages; the last editions date from the middle or end of the seventeenth century, practically all in Latin. Some texts are in Greek, not a few very important ones. That gave me no end of work, but the result was most satisfactory, because it showed me the development of our unconscious relations to the collective unconscious and the variations our consciousness has undergone, and why the unconscious is concerned with these mythological images. …

… Of course I cannot tell you in detail about alchemy. It is the basis of our modern way of conceiving things, and therefore it is as if it were right under the threshold of consciousness. It gives you a wonderful picture of how the development of archetypes, the movement of archetypes, looks when you see them as if from above. From today you look back into the past, and you see how the present moment has evolved out of the past. Alchemical philosophy – it sounds very curious. We should give it an entirely different name. It does have a different name, it is called Hermetic philosophy, though of course that conveys just as little as the term alchemy. It is the parallel development, as Gnosticism was, to the conscious development of Christianity, of our Christian philosophy, of the whole psychology of the Middle Ages. ~Carl Jung