The physiognomical manual of John Caspar Lavater provides rules for judging by the phsyiognomy: is someone’s nose a little to the left? perhaps their eyebrows are not quite symmetrical? or their ears are set far back on their head? These are all guides to their inner character, how they are likely to behave in almost any situation.
Lavater’s handbook provides not only visual illustrations so you can match the face against the characteristic, it also promises “One Hundred Physiognomonical [sic] Rules” to help you detect obstinacy, worthless insignificance, hypocrisy, and voluptuaries among others.
Flip through the pages of Lavater’s guidebook below or follow this link to read Essays on physiognomy (1853).