Read Concerning Being And Essence Online

PREFACE xxi 

St. Thomas agrees with Aristotle that it is absurd to seek 
knowledge and simultaneously the means for obtaining knowl- 
edge. 2 But now it is a basic postulate in Aristotelian analysis 
that propositions break up into their terms. Such terms are 
not logical atoms without intentional structure, but signs which 
signify substances and thus such signs belong to the level of 
intentions or modes of signification. It is then the right, good 
and noble thing that the De Ente et Essentia should invoke the 
investigation of being and essence by reference to intention. 
Modes of signification have a similitude or formal analogy to 
the modes of being in natures, and the intellect is said to 
know, that is, to understand the thing when it has abstracted 
the similitude of its being inasmuch as it is a substantial unity. 

Logic deals with entia rationis, beings of the conceptual order. 
But the res naturae, the thing as individuated, is independent 
of the rational order. Essence exists one way in things, but in 
another way in the mind. Rational essence is composed of signs 
which stand to the thing signaled (the nature), and hence 
the rational essence is by composition and division, but the 
nature of the thing exists as indi visibly individuated. The divis- 
ibility and separation is in the order of abstraction or analysis 
and not literally in the thing in this mode. When one measures, 
for example, a table he does not divide and compose the table, 
but the act of analysis runs thus: a unit (imposed) of the table 
is to its total length as one is to (say) twelve. 8 The predicables 

2 Aristotle, Metaphysics, i, 995 a 12. 
St. Thomas Aquinas, In II Met., i. 5. 

3 A few Aristotelian sources may be helpful: In regard to unified wholes: 
". . . those which are so (scil. wholes) by nature are wholes in a higher 
degree than those which are so by art (scil. fabrication), as we said in 
the case of unity also, wholeness being in fact a sort of oneness." Met. 
1023 b 33 "Now most things are called one because they either do or 
have or suffer or are related to something else that is one, but the 
things that are primarily called one are those whose substance is one, 
and one either in continuity or in form or in definition. . . . While in a