Besides, whoever keeps the future in front of him and the past at his back is doing something else that's hard to imagine. For the image implies that events somehow already exist in the future, reach the present at a determined moment, and finally come to rest in the past. But nothing exists in the future; it is empty; one might die at any minute. Therefore such a person has his face toward the void, whereas it is the past behind him that is visible, stored in the memory.