The founder of American psychology, who mapped habit, attention and belief — and wrote the frankest account of melancholy in English.
Rome's richest philosopher, writing you letters about how little wealth matters — and knowing exactly how that sounds.
Tutor of Alexander, cataloguer of animals and constitutions, who taught that we become good by practice and find the right act at the mean.
The sceptic who showed that no argument proves tomorrow will resemble today — then admitted that dinner and a game of backgammon cure the doubt inside an hour.