 Finally, in modal logic, Theophrastus seems to have deviated from the Aristotelian doctrine. In contrast to Aristotle, Theophrastus defined possibility as no longer entailing non-necessity (fr. 101 FHS&amp;G). He recognized that the problematic universal negative proposition “A possibly holds of no B” converts, just as the assertoric universal negative and the necessary proposition do (frs. 102A–C FHS&amp;G). Furthermore, he introduced the in peiorem rule for mixed modal syllogisms, according to which the conclusion always has the same modal character as the weaker of the premises, assuming that possibility is weaker than actuality, and actuality is weaker than necessity (frs. 106–107 FHS&amp;G).