  So according to Boethius the basic feature of Philonian modalities is some intrinsic capability of the propositions to be or not to be true or false. That this feature is intrinsic is plain from the phrases ‘by its own nature’ and ‘in itself’. In one source, both phrases are used to characterize Philonian possibility (Simplicius, On Aristotle's Categories 195); hence both phrases may have originally applied to all four accounts.