The individuation process, as the way of development and maturation of the psyche, does not follow a straight line, nor does it always lead onwards and upwards. The course it follows is rather stadial, consisting of progress and regress, flux and stagnation in alternating sequence. Only when we glance back over a long stretch of the way can we notice the development. If we wish to mark out the way somehow or other, it can equally well be considered a spiral, the same problems and motifs occurring again and again on different levels.

p. 216; cited by Jolande Jacobi (1983) The way of individuation. p. 34, translation of Der Weg zur Individuation. Rascher, Zürich 1965 - Theory of Experimental Inference (1948)