Nothing is the cause of it.

   When a ripe apple falls, What makes it fall ? Is it gravity , pulling it down to earth ? A Withered stalk ? Drying The action of the sun? Increased weight ? A breath of wind ? Or the boy under the tree who wants to eat it?
Nothing is the cause of it. It is just the coming together of various Necessary Conditions for any living , organic, elemental event to take place. And the botanist who finds That the apple has fallen Because of the onset of decay in its cellular structure, and all the rest of it , will be no more right or wrong Than The boyunder the tree who says the apple fell Because he wanted to eat it and prayed for it to fall.

Leo Tolstoy . War & Peace. Chapter III, Part I, Chapter I.