For what purpose humanity is there should not even concern us: why you are here, that you should ask yourself: and if you have no ready answer, then set for yourself goals, high and noble goals, and perish in pursuit of them!
We are responsible for what we are, and whatever we wish ourselves to be, we have the power to make ourselves. If what we are now has been the result of our own past actions, it certainly follows that whatever we wish to be in the future can be produced by our present actions; so we have to know how to act.