Q. Why did some of Antiochus’s subjects call him “The Mad King”?
A. Leaders all have their detractors. In the case of Antiochus they employed a play on words. Instead of “Epiphanes” (“god manifest”) they called him “Epimanes” (mad one). It may be that he showed signs of instability, or, more probably, they thought his policies irrational.
One wonders why his madness, whatever its nature, expressed itself in hatred of Jews. It is likely that his endeavours to unify his kingdom with hellenistic cultural norms were frustrated by Jewish non-compliance. The Jews objected to the externalities of Hellenistic life such as sporting competitions in which athletes competed naked, causing embarrassment to men who had been circumcised.
Jewish reservations about hellenisation went further, however. Jews could not worship a pantheon, or substitute human reason for Divine revelation. They could not deify shape and beauty, and downplay goodness and morality. If the Jews had gone along with the king’s edicts, it would have been they who would have been mad.