From The Idiot:
How can you tell, Bakhmutov, what significance such a communion of one individual with another will have in the latter's destiny? For here you have a whole lifetime, with an infinity of ramifications which are hidden from us. The best chess player, the very cleverest, can think only a few moves ahead; a French player who could calculate ten moves ahead was written about as a marvel. But how many moves are there here and how much is unknown to us? In planting your seed, in offering your "alms," your good deed in whatever form, you are giving away part of your individuality and receiving part of another's; you are communign one with another already with a certain mutual consideration, andyou will be rewarded by knowledge and by the most unexpected discoveries. You will certainly in the end come to look upon what you do as a science; it will absorb your whole life and perhaps fill it entirely. On the other hand, all your thoughts, all the seeds planted by you, which perhaps you have forgotten, will take root and grow; whoever received them from you will pass them on to another. And how will you know what part you will have played in shaping the destiny of mankind?