 A twelfth-century commentary on the Perihermeneias reports Porphyry as saying that at the time of Aristotle, there was a great debate over the principal signification of utterances: was it ‘res’ (things) or incorporeal natures (Plato) or sensus (sensations) or imaginationes (representations) or intellectus  (concepts)?[9]  In fact, medieval philosophers of language were heir to two conflicting semantic theories. According to Aristotle, the greatest authority from the ancient world, words name things by signifying concepts in the mind (Boethius translated Aristotle's term as passiones animae – affections of the soul) which are likenesses abstracted from them. But Augustine, the greatest of the Church fathers, had held that words signify things by means of those  concepts.[10]  This led the medievals to the question: do words signify concepts or things? The question had already been asked by Alexander of Aphrodisias and his answer was transmitted to the medievals in Boethius' second commentary on Aristotle's Perihermeneias (De Interpretatione): “Alexander asks, if they are the names of things, why has Aristotle said that spoken sounds are in the first place signs of thoughts … But perhaps, he says, he puts it this way because although spoken sounds are the names of things we do not use spoken sounds to signify things, but [to signify] affections of the soul that are produced in us by the things. Then in view of what spoken sounds themselves are used to signify he was right to say they are primarily signs of them” (tr. Smith, pp.  36–37).[11]  So words primarily signify concepts.