Mulder: Scully, did you ever have one of those days you wish you could rewind and start all over again from the beginning?
Scully: Yes. Frequently. But, I mean, who’s … who’s to say that if you did rewind it and start over again that it wouldn’t end up exactly the same way?
Mulder: So you think it’s all just fate? We have no free will?
Scully: No, I think that we’re free to be the people that we are - good, bad or indifferent. I think that it’s our character that determines our fate.
(Season 6, ep. 14 “Monday”)