Existentialists such as Jean-Paul Sartre often contrast existence and essence. When they assert existence precedes essence, they regard essence as an ideal nature of the real existence.
1. The ambiguity of esse
But etymologically essence (essentia in Latin) derives from be (esse). In what respect does exist differ from be? What relation does essence bear to be?
We use be as an intransitive verb sometimes without complement and sometimes with it.
1. The car is in my garage. (bemeaning exist)
2. The car is red. (beas a copula)
The copula’s connection of subjects to predicates is sometimes analytic and sometimes synthetic. As not all cars are red, the second sentence is synthetic. However,
3. A car is a vehicle with three or four wheels driven by a motor.
is analytic, if it is the definition of cars.
2. Esse and Existentia
Ancient Greek philosophers asked, "What is X?" to investigate the essence of X. That is to say, the essence is expressed by the definition, "X is… . " Let’s paraphrase this sentence in "X is, and it is… ." You may be inclined to say the former berepresents the existence, while the latter berepresents the essence of X.
But do all beings really exist? No. Not all subjects exist. For example, the subject of Chimera is a monster made up of parts of different animals. does not exist, though Chimera is at least as an imaginary being. Nor can you say zero is not. If it were not for zero, you cannot even speak of it. The signified of some conceptions do not exist, but are ideally. So, not all beings exist.
3. Substance stands out as existence
Etymologically, existence is ex-sistere (stand out) and substance is sub-stare (stand under). Substance as an ideal essence stands under real phenomena and it exists when it stands out from ideal possibilities.