 Thus, according to Ockham, formal consequences are those that hold in virtue of middles, be they intrinsic or extrinsic. A consequence holds immediately in virtue of an intrinsic middle when it holds in virtue of the truth of a different sentence formed from its terms. For example, ‘Socrates is not running, therefore a man is not running’ holds in virtue of this middle: ‘Socrates is a man’, since if ‘Socrates is a man’ is not true, the consequence does not hold. These are typically enthymematic consequences, i.e. consequences with a ‘missing premise’ (with the additional premise, they become a valid syllogism). An extrinsic middle, by contrast, is a sentence not containing the terms that form the antecedent and the consequent of the putative consequence, but which is a general rule describing the ‘fact’ that warrants the passage from the antecedent to the consequent (reminiscent of Boethius’ maximal propositions), and which concerns the form of sentences. Ockham’s example of a consequence holding immediately in virtue of an extrinsic middle is ‘Only a man is a donkey, therefore every donkey is a man’, which holds in virtue of this general rule: ‘an exclusive and a universal with transposed terms signify the same and are convertible’.