Over the last few years I've had a number of discussions with friends (jamie and C spring immediately to mind) as to whether or not any of us have free will. Now, I don't believe in destiny, mainly because as I understand the term destiny implies a deliberate or at least consciously directed path for our lives to follow (the fact that destiny is generally invoked by those seeking to justify what they have, justify what they want, or justify the damage they've done in getting what they have or grabbing for what they want, is another story). You could extrapolate the word to cover any philosophy that we're stuck on rails and can't get off, but I prefer the term "determinism". It's the difference between believing America was deliberately created, and knowing that I find it if I hit the Atlantic and head West.
(Well, I'd almost certainly drown or get lost were I to try it; but you get the point).
My belief in determinism stemmed from the assumption that there is no such thing as randomness in the universe. There's a lot we don't know, and as Heisenberg reminds us, much that we physically cannot know. Unknowable and random are not the same thing, though; and if every action has a non-random consequence, then the universe just becomes one big horribly complex game of billiards, and nothing ever knocks us off the rails.
People tend not to like this argument, for obvious reasons (much like those people who insist on believing in God because the alternative is too horrible to consider; I'm looking at you, Big G). But the only convincing point against it I've heard is the argument that most scientists think that when you get down to the quantum level things really are happening in a messed-up way that is genuinely random. Whether these microscopic slow dances of elementary particles can possibly affect us within our lifetimes (as oppose to the coding in our DNA and our upbringing essentially ticking all the boxes in advance) is an interesting question, but it does invalidate the idea that there is no such thing as the truly random.
I note with interest, though, that New Scientist (I nearly wrote this week's New Scientist, until I remembered that I found it in the coffee room this morning and for all I know it was months old and only just been released from the office of whichever staff member keeps stealing them) suggesting new evidence has been found that this stuff might be deterministic after all. I only had time to read the first few paragraphs, and I recognise that for a magazine dedicated to science, NS tends to play fast and loose with anything so inconvenient as a fact, but this might bear a closer look.
Maybe I was right all along, and we have no genuine control over our lives. But as an old friend pointed out to me years ago, since there's no way we can predict what will happen, and since I don't believe anyone or anything intended for my life to take this path, then what exactly does it matter?
Update: I went and checked. It was the 22nd March issue, and essentially said "We haven't yet disproved causality, despite what those douches over in quantum theory keep saying". Good to know.