The Zurich pastor, philosopher, and writer Johann Caspar Lavater (1741-1801) did not invent physiognomy. Physiognomy signifies the making of assumptions about a person's inner qualities, for example their character, based on their outer appearance. Such attempts can already be found in Aristotle and Paracelsus. But it was Lavater who turned it into an allegedly scientific method: By means of a huge archive of images, he tried to show how one could recognize human character on the basis of facial features, skull proportions and body shapes. Lavater was also the first to publish Dutch physician Petrus Camper’s “facial angle” theory, which claimed that one could determine with scientific-mathematical accuracy the proximity of the "human races" to the animal. Thus, Lavater popularized the racial theories of his contemporaries.

Lavater's main work, ‘Physiognomische Fragmente zur Beförderung der Menschenkenntnis und Menschenliebe’ (‘Physiognomic Fragments to Promote Knowledge of Human Nature and Love for Mankind’), was popular. The physiognomy described in it laid an important foundation for modern racism, anti-Semitism, and the devaluation of everything that did not conform to prevailing norms. Non-European people were portrayed as supposedly biologically – and thus by nature – "inferior races". In this way, Lavater shaped a way of thinking that guided racial theorists and anti-Semites right up to the Nazi era.

Lavater's work was published in the 18^th century and was received enthusiastically. By the beginning of the 19^th century, his work had been translated into numerous languages and published in several European countries as well as in North America. In the post-Enlightenment bourgeoisie of the 19^th century, Lavater’s physiognomy became a "science", a social game, and a downright obsession that lasted well into the 20^th century, showing its traces to this day.

Lavater is often defended ‍against the accusation of racism with the argument that he was a child of his time. The slave traders and slave owners of the 18^th and 19^th centuries are often defended in the same manner. However, Lavater's theory was already controversial during his lifetime (as was slavery at the time of its practice). The Swiss writer Ulrich Bräker, for example, wrote to Lavater: "Ich bin Dir gut, von Herzen gut, und möchte Dich um viel nicht böse machen. Aber die Schädel sind mir grüsig und ’s wird mir übel" ("I mean you well, from the heart, and would not want to anger you. But the skulls are repulsive to me and make me feel sick"). Where Bräker merely had an uneasy feeling, his contemporary and physicist Georg Christoph Lichtenberg was uncannily clear-sighted:  "Wenn die Physiognomik das wird, was Lavater von ihr erwartet, so wird man Kinder aufhängen, ehe sie die Taten getan haben, die den Galgen verdienen" ("If physiognomics becomes what Lavater expects of it, children will be hanged before they have done the deeds that deserve the gallows").

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