<P> To claim that existence precedes essence is to assert that there is no such predetermined essence to be found in humans, and that an individual's essence is defined by the individual through how that individual creates and lives his or her life . As Sartre puts it in his Existentialism is a Humanism: "man first of all exists, encounters himself, surges up in the world--and defines himself afterwards". </P> <P> Existentialism tends to focus on the question of human existence and the conditions of this existence . What is meant by existence is the concrete life of each individual, and their concrete ways of being in the world . Even though this concrete individual existence must be the primary source of information in the study of people, certain conditions are commonly held to be "endemic" to human existence . These conditions are usually in some way related to the inherent meaninglessness or absurdity of the earth and its apparent contrast with our pre-reflexive lived lives which normally present themselves to us as meaningful . A central theme is that since the world "in - itself" is absurd, that is, not "fair", then a meaningful life can at any point suddenly lose all its meaning . The reasons why this happens are many, ranging from a tragedy that "tears a person's world apart", to the results of an honest inquiry into one's own existence . Such an encounter can make a person mentally unstable, and avoiding such instability by making people aware of their condition and ready to handle it is one of the central themes of existentialism . Albert Camus, for instance, famously claimed in Le Mythe de Sisyphe that "there is only one truly serious philosophical problem, and that is suicide". </P> <P> Aside from these "psychological" issues, it is also claimed that these encounters with the absurd are where we are most in touch with our condition as humans . Such an encounter cannot be without philosophical significance, and existentialist philosophers derive many metaphysical theories from these encounters . These are often related to the self, consciousness and freedom as well as the nature of meaning . </P> <P> The Marxist formulation of being preceding consciousness was contradicted by Václav Havel in his 1990 speech to the U.S. Congress, in which he, speaking of his experience of living under a totalitarian system, averred that "Consciousness precedes being, and not the other way around, as the Marxists claim ." </P>

In the excerpt above what is the best explanation for the phrase existence precedes essence