Facticity is a concept defined by Sartre in Being and Nothingness as that "in-itself" of which humans are in the mode of not being. This can be more easily understood when considering it in relation to the temporal dimension of past: One's past is what one is in the sense that it co-constitutes oneself. However, to say that one is only one's past would be to ignore a large part of reality (the present and the future), while saying that one's past is only what one was would entirely detach it from them now. A denial of one's own concrete past constitutes an inauthentic lifestyle, and the same goes for all other kinds of facticity (having a body (e.g. one that doesn't allow a person to run faster than the speed of sound), identity, values, etc.). Facticity is both a limitation and a condition of freedom. It is a limitation in that a large part of one's facticity consists of things one couldn't have chosen (birthplace, etc.), but a condition in the sense that one's values most likely will depend on it. However, even though one's facticity is "set in stone" (as being past, for instance), it cannot determine a person: The value ascribed to one's facticity is still ascribed to it freely by that person. As an example, consider two men, one of whom has no memory of his past and the other remembers everything. They have both committed many crimes, but the first man, knowing nothing about this, leads a rather normal life while the second man, feeling trapped by his own past, continues a life of crime, blaming his own past for "trapping" him in this life.
There is nothing essential about his committing crimes, but he ascribes this meaning to his past. However, to disregard one's facticity when one, in the continual process of self-making, projects oneself into the future, would be to put oneself in denial of oneself, and would thus be inauthentic. In other words, the origin of one's projection will still have to be one's facticity, although in the mode of not being it (essentially). Another aspect of facticity is that it entails angst, both in the sense that freedom "produces" angst when limited by facticity, and in the sense that the lack of the possibility of having facticity to "step in" for one to take responsibility for something one has done also produces angst. What is not implied in this account of existential freedom, however, is that one's values are immutable; a consideration of one's values may cause one to reconsider and change them. A consequence of this fact is that one is responsible for not only one's actions, but also the values one holds. This entails that a reference to common values doesn't excuse the individual's actions: Even though these are the values of the society of which the individual is part, they are also her/his own in the sense that she/he could choose them to be different at any time. Thus, the focus on freedom in existentialism is related to the limits of the responsibility one bears as a result of one's freedom: the relationship between freedom and responsibility is one of interdependency, and a clarification of freedom also clarifies that for which one is responsible. The existentialist concept of freedom is often misunderstood as meaning that anything is possible and where values are inconsequential to choice and action. This interpretation of the concept is often related to the insistence on the absurdity of the world and the assumption that there exist no relevant or absolutely good or bad morals. However, that there is no external power exerting forced moral action in the world in-itself does not mean that there are no good/evil morals; for the only force rewarding, considering, and following logic, reason, and counter-degenerateism are existentialists themselves... for arbitrary values serve no purpose to follow