In the course of evolution, it constantly happens that, independently of each other, two different forms of life take similar, parallel paths in adapting themselves to the same external circumstances.

Whenever we find, in two forms of life that are unrelated to each other, a similarity of form or of behaviour patterns which relates to more than a few minor details, we assume it to be caused by parallel adaptation to the same life-preserving function.

The father-mother family with two children isolated in a city flat is already insufficient.

From a neighbour, I got a one-day-old duckling and found, to my intense joy, that it transferred its following response to my person. At the same time, my interest became irreversibly fixated on water fowl, and I became an expert on their behaviour even as a child.

Behind the masks of total choice, different forms of the same alienation confront each other.

Similar things are drawn to each other.