John,
Seeing your message caused me to reply. I have a purpose in mind when I do so, which explains the typing behavior you see before you. We do not have to go back forever in time to be satisfied with this explanation do we? 

Are you suggesting that a goal or "terminus", as you put it, is necessary to give any explanations at all? Surely there are causal explanations that don't involve goal-directed behavior, like the predictable celestial mechanics of our solar system. 

-dcd