h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Many have suggested that fate exists, not based purely on anecdotal evidence or because tracing a logical sequence of events makes their brains hurt but based on the assumption that we live in a rational universe, things do not occur spontaneously, they occur because something caused them, even our own thoughts are just biochemical reactions caused by other biochemical reactions(memory, values etc.) or by external stimuli, so in the sense that one event causes another which itself will cause another and so on, one initial set of events has only one possible conclusion via only one possible series of events inbetween. In that sense everthing is predetermined, theoretically given all relevent information we extrapolate the entire history of the universe and trace the future through to end of the universe itself. In a sense this is what weathermen, paleontoligists, archaeologists and investors try to do, although they do do it in a very clumsy and inacurate way as to do it perfectly would make ones brain hurt.

This causality of all events can be called fate. Because fate is the causality of everything that happened and is happening and will happen. Given that chance does not exist we can say that fate is the only explanation for everything that happened and is happening and will happen.