What is meant here by saying that existence precedes essence? It means that, first of all, man exists, turns up, appears on the scene, and, only afterwards, defines himself.... Not only is man what he conceives himself to be, but he is also only what he wills himself to be after this thrust toward existence. Whereas a table is a table is a table, humans have no preexisting essence and so define themselves,
Gordon Marino, Ethics: The Essential Writings
existentialism