 It is useful at this point to take note of the three different functions the thin particular or substratum might fulfil. Its role might be (i) to bind the properties into a unity, so that they do not ‘fall apart’: (ii) to individualise them, if they are universals: (iii) to carry one across the categorial barrier from property to substance; that is, to be what it is that makes something to be in the category of substance.