None of the important questions in life can be resolved by a rational person through considerations of the immediate results and consequences. He cannot be satisfied by the same things that guide an animal’s behaviour. Man may regard himself as an animal living among animals, by the day, or he may think of himself as a member of a family, or society, or a nation that lives for centuries. Or he may find himself obliged (because his reason drives him irresistibly to it) to regard himself as a part of an infinite universe, living in infinite time. And, therefore, in respect of the infinitely small phenomena of life that influence his behaviour, a rational person must do what in mathematics is called integration: that is, establish a relation to the immediate issues of life, a relation to the entire infinite universe in time and space, conceiving of it as a whole. And the relationship established by man to that whole, of which he feels himself a part and from which he draws guidance for his behaviour, is that which has been, and is called religion. And therefore religion has always been, and cannot cease to be, an essential and indisposable condition of the life of rational humanity.


- Lev Nikolayevich Tolstoy