The most notable supporter of the existentialist movement was the French philosopher Jean-Paul Sartre. His belief that actions need to be considered with reason, justification and an understanding that one’s decision will have an impact on the rest of society are crucial in this theory. The basic concept created by this movement was “existence prior to essence.” That is, everything exists before meaning has been attributed to the thing. Therefore, humans exist and it is only when things are defined and acted upon that they can hold any actual meaning. When dealing with the self, Sartre believes that a man exists and it is through all of his actions that he is able to define who he is and before actions are executed, the man is nothing more than a thought.
Also, one needs to be aware that they are autonomous and self-determining creatures. To maintain a society that will continually promote the greatest end, this self-governing agency within the rational person must be taken into account. It is because people are able to take a subjective position and weigh the benefits to the consequences of a given situation, that this theory is functional. As a generalized norm, it is safe to assume that the furthering of human life and happiness is the greatest achievable good. This autonomy of man, or what can also be described as free will, is what constructs a successful community. Because man is able to decide what they are going to become by consciously making a decision to act one way or another, a set of accepted standards are formed for the whole population to follow. Sartre does specify that every man creates a specific universal concept pertaining to himself, but it is the collection of all of these widespread images that builds a society.
Thoughts are not enough and only provide a frame of reference for the being while using this theory. In order for any good to occur these thoughts must be expressed. The categorical imperative established by Immanuel Kant, “act as if the maxim of your action were to become by your will a universal law of nature” is supportive to this case. This Kantian theory can be compared to Sartre’s idea that the results of my actions impact all of humanity. With this justification, it is assumed that the actions done by one aim to promote the good of the universe. There is a sense of duty to the universe and this compels one to act only in such a way that they could at the same time will unto everyone. When seeking the greatest good, one must break away from the accepted standard and consistently aim for better. It is in human nature to use the freedom within to determine the things that ought to be. Sartre stresses the involvement of reason leads man to always choose good, because one will never choose an evil willingly, and therefore what is good for one is at the same time good for all.
Special attention needs to be paid to the element of accepting responsibility for your actions and your faults in this theory. The existentialists believes that every human needs to claim ownership to all behavior acted upon. Again, this plays on the idea that all humans are autonomous and that good or bad actions preformed are decided before the performance is initiated. Failing to accept ownership of one’s actions is unlawful within this theory and is a disservice to society. Man is only able to become authentic and genuine when one claims their actions. Here, Sartre understands that the outcomes may not always be enjoyable, but in the end, at least one is able to say that they were honest and sincere about their decisions.