Alexander (15) Philalethes (‘Truth-lover’), a physician (fl. later 1st cent. bce?), succeeded *Zeuxis (3) as leader of the Asian branch of *Herophilus's ‘school’. Alexander's views on digestion, on various diseases, and on invisible ducts (πόροι) dispersed throughout the body have much in common with those of *Asclepiades (3) of Bithynia, as the Anonymus Londinensis and the Methodists recognized. However, only one problematic later Latin source explicitly identifies Alexander as a ‘pupil’ (discipulus) of Asclepiades. In his Gynaecia Alexander asserted that there are no diseases peculiar to women, thus siding with both Herophilus and Asclepiades on this controversial issue (see apollonius (10) mys; demetrius (21) of apamea; erasistratus). He agreed with Herophilus and Aristotle that male ‘seed’ (σπέρμα) has its origin in the blood. In his doxographic work Τὰ ἀρέσκοντα (‘Opinions’), he made an influential distinction between an ‘objective’ and a ‘subjective’ definition of the pulse. He argued for a modified ‘objective’ version of the pulse definitions advocated by the Herophileans *Bacchius, *Zeno (7), and *Chrysermus.