Illustrations of medieval stereotypes of personalities based on facial features. Physiognomy is the assessment of a person's character or personality from his or her outer appearance, especially the face. The practice was accepted by the ancient Greek philosophers, but fell into disrepute in the Middle Ages when practised by vagabonds and mountebanks. It was revived and popularized by Johann Kaspar Lavater before falling from favor again in the late 19th century. Physiognomy as understood in the past meets the contemporary definition of a pseudoscience.