Man, do not pride yourself on superiority to the animals; they are without sin, and you, with your greatness, defile the earth by your appearance on it, and leave the traces of your foulness after you—alas, it is true of almost every one of us! Love children especially, for they too are sinless like the angels; they live to soften and purify our hearts and as it were to guide us.
 Fyodor Dostoyevsky, The Brothers Karamazov (1880). copy citation

Context

“at last to love the whole world with an all-embracing love. Love the animals: God has given them the rudiments of thought and joy untroubled. Do not trouble it, don't harass them, don't deprive them of their happiness, don't work against God's intent. Man, do not pride yourself on superiority to the animals; they are without sin, and you, with your greatness, defile the earth by your appearance on it, and leave the traces of your foulness after you—alas, it is true of almost every one of us! Love children especially, for they too are sinless like the angels; they live to soften and purify our hearts and as it were to guide us. Woe to him who offends a child! Father Anfim taught me to love children. The kind, silent man used often on our wanderings to spend the farthings given us on sweets and cakes for the children. He could not pass by a child without emotion.” source