relatively to the creaturely production and sustentation that we find, for instance, in man. Of these substances there are two kinds : the res cogitans and the res extensa.
The Being of that substance whose distinctive proprietas is presented by extensio thus becomes definable in principle ontologically if we clarify the meaning of Being which is 'common' to the three kinds of substances, one of them infinite, the others both finite. But "... nomen substantiae non convenit Deo et illis univoce ut dici solet in Scholis, hoc est ... quae Deo et creaturis sit communis."xiii Here Descartes touches upon a problem with which medieval ontology was often busied-the question of how the signification of "Being" signifies any entity which one may on occasion be considering. In the assertions 'God is' and 'the world is', we assert Being. This word 'is', however, cannot be meant to apply to these entities in the same sense (συνωνύμως, univoce) , when between them there is an infinite difference of Being ; if the signification of 'is' were univocal, then what is created would be viewed as if it were uncreated, or the uncreated would be reduced to the status of something created. But neither. does 'Being' function as a mere name which is the same in both cases : in both cases 'Being' is understood. This positive sense in which 'Being' signifies is one which the Schoolmen took as a signification 'by analogy', as distinguished from one which is univocal or merely homonymous. Taking their departure from Aristotle, in whom this problem is foreshadowed in prototypical form just as at the very outset of Greek ontology, they established various kinds of analogy, so that even the 'Schools' have different ways of taking the signification-function of "Being". In working out this problem ontologically, Descartes is always far behind the Schoolmen ;xiv indeed he evades the question. " ... nulla eius (substantiae ) nominis significatio potest distincte intelligi, quae Deo et creaturis sit communis. "xv This evasion is tantamount to his failing to discuss the meaning of Being which the idea of substantiality embraces, or the character of the 'universality' which belongs to this signification. Of course even the ontology of the medievals has gone no further than that of the ancients in inquiring into what "Being" itself may mean. So it is not surprising if no headway is made with a question like that of the way in which "Being" signifies, as long as this has to be discussed on the basis of an unclarified meaning of Being which this signification 'expresses'. The meaning remains unclarified because it is held to be 'self-evident'.
Descartes not only evades the ontological question of substantiality altogether; he also emphasizes explicitly that substance as such—that is to say, its substantiality—is in and for itself inaccessible from the outset [vorgängig]. "Verumtamen non potest substantia primum animadverti ex hoc solo,