 In systematic terms, Boethius’ change makes no difference and all medieval logicians writing after him adopted it, even though it makes the first figure syllogisms less evident. According to Aristotle, the first syllogism of the first figure (Barbara) should read: ‘A belongs to all B, B belongs to all C; therefore A belongs to all C’. This is obviously valid by the transitivity of inclusion. But if we line up the same syllogism using Boethian formulation we get: ‘Every B is A, Every C is B; therefore Every C is A’. This is not at all as obvious and we have to switch the places of the premises to get the same transitivity characteristic: ‘Every C is B, Every B is A; therefore Every C is A’. Beyond this small but significant change, Boethius does not contribute much to the theory, though he is a little more interested than Aristotle in the different kinds of conversion. His hypothetical syllogistic is, on the other hand, rather novel.