“Watch your thoughts; they become your words. Watch your words; they become your actions. Watch your actions; they become your habits. Watch your habits; they become your character. Watch your character for it will become your destiny.” - Source Unknown
“If man, as the existentialist conceives him, is indefinable, it is because at first he is nothing. Only afterward will he be something, and he himself will have made what he will be. Thus there is no human nature, since there is no God to conceive it. 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.” – Jean Paul Sartre
Life is not predetermined. There is no such thing as destiny. Humans can always choose to go against their nature... in a single second they can make a choice they never would normally, it's simply that routine and stability are appealing and they have their own natural inclinations, however, so does change.
Their love of stability sets up a sort of determinism, as they tend to choose the same way for similar situations hoping for similar results.
For example, we go to a job every day hoping to get the same reward at the end of the week. We know if we work we will get paid. We want to be paid and therefore choose to work. This isn’t that we are destined to work, we simply continue to choose to so. If we were to not be paid for our labors, or get paid rather infrequently, we might not always choose to do so in favor of something more stable. Stability in results leads to stability in choice. It's why Monday night we always tune into the same TV shows, it's why come back to our favorite restaurants... we crave something we had before and the stability it brings.
Our love of change prevents us from that however. It’s a force that acts upon us with equal measure. Our irrationality and constant drive for better makes us experiment. Why do we quit the job we love so much? Why do we try new experiences and go to the newest restaurants when the experiences we have are good and our favorite restaurant is good enough? We, first of all, say we get bored with such things. We say that we need to expand our horizons. People are curious by their very nature and this fuels our need for change as well. Change boosts our morale and balances us out. Change makes us choose for variety’s sake.
Our choices in themselves also present both determinism and free choice as well. Basic cause and effect dictates their deterministic qualities. Because of my choice the effect is__________. We must live with the results of our choices. When there is an action there is a reaction. Sometimes determinists use this to point out that we are only reacting to things that happened before us which in turn are reactions to things which happened before that down to the very first action: the original cause. People however, aren't as simple as that. To paraphrase Immanuel Kant, people are "ends" and not "means"; we have a choice within our reactions. We can choose to react either in a positive manner to a set of actions presented to us or negatively. If I were found the victim of a crime, I could either use my victim status to gain pity from others, or I could be empowered by it. This is true for all sets of choices in our lives, from the life altering (the death of a loved one perhaps) to the most insignificant (gaining a few pounds). We are not purely reactionary. We can choose our reactions.
In addition our personal experiences and the insight we gain from the experience of others also affects our free will. Our knowledge always keeps us changed even when our choices do not. In choices involving others, the situation is relative and the choices, even though they may seem the same, the people involved in the choices are different. If we asked someone for a favor before (perhaps to watch our pets while we are on vacation) and they were not reliable, we would not ask them again. However, if they were to do well, the next time the very same choice presents itself, we’ll ask.
Despite this from seeming like determinism I must point out that acting on previous experiences or acting in accordance with desires are only inclinations. Inclination and determinism are two different things. Inclinations are the choices we are most likely to take, whereas determinism robs us of choice. It’s when we fall into our inclinations so deeply that we forget about choice that we become self-determined.
In short, I always believe we are free, save from these two forms of determinism: the results of our actions and our inability to sometimes see our choices. In these we are slaves to a somewhat determinable lifestyle. Otherwise we're 99% predictable to act in certain manners that give the illusion of determinism.
To respond to Dave and clear up a few issues, the whole existentialism/determinism debate has raged on for ages. It’s very inconclusive as are most things in the philosophical arena. These are simply my views. The problems with a deterministic outlook, at least in my opinion, I’ll hope to explain here.
First of all, determinism, although saying that all events/actions/volitions are already determined, and whether or not “choice” exists (soft determinism, which says choices exist but the choice made is already determined, hard determinism, which says choice doesn’t exist, but is in fact, an illusion) the results are pretty much knowable. They rely on events that have already happened to point out the relationship of cause and effect to prove their point. They also, however, say that results to happen as of yet are unknowable because it is impossible for human beings to know all the causes that exist within the given universe. Kind of sounds like they want to have their cake and eat it too. An existentialist points out that in that moment when choice can be made, there are a variety of causes that could affect a person to choose one way or another. Sartre gives a great example of this in his “Existentialism as a Humanism” where he talks of a student who approached him, asking whether or not to enlist to fight in the war (Sartre, being in France during WWII at the time of the incident). The student might decide not to go to war because he must take care of his sick mother at home, or perhaps he may enlist, leaving his sick mother, thinking his country needs him more. There are many reasons that exist inside a person at the time of choosing but it is ultimately us who chooses. A determinist would be just as powerless to say which cause would be “determined” to him in this situation until after he chooses. Only then would a determinist say why that choice was fated to him. Sounds kind of screwy, no?
Secondly, and this leads more into my reasoning behind free will in a god subsisting world, without free will, there’s no value behind our actions or our lives. We are simply puppets, some cases, playing out to a higher plan, devoid of the ability to give ourselves purpose or value. We are nothing more than another cog in the machinations of fate. To choose is pointless and to attach value to any matter is absurd. It’s a rather dismal outlook on life. However, just as determinists would argue that free will exists to simply comfort us, existentialists believe determinism does the same thing by relieving us of the burden of choice. (see bad faith)
Thirdly, Sartre was an atheist, yet not all existentialists were like him. There were a number of existentialists (who if I remember correctly, were considered the German faction, whereas the French faction were like Sartre) who believed in a Deus (most of them Christian) without compromising free will and choice. In fact, if you examine religion on the whole, if god has a plan, and gives us no ability to choose, then why would he/she/it give us a set of beliefs to follow? When you are determined and fated to kill another man, why created within the Ten Commandments, a rule against doing so? Morality is a mute and pointless issue in a determined world.
Another side of the debate, which I don’t feel like going into, unless someone wishes me to, is the difference between fatalism and determinism.