“And yet it is complete, it is decisive. Look! I repeat to you that all hereditary cases are to be found there. To establish my theory, I had only to base it on the collection of these facts. And indeed, the marvelous thing is that there you can put your finger on the cause why creatures born of the same stock can appear radically different, although they are only logical modifications of common ancestors. The trunk explains the branches, and these explain the leaves. In your father Saccard and your Uncle Eugène Rougon, so different in their temperaments and their lives, it is the same impulse which made the inordinate appetites of the one and the towering ambition of the other. Angelique, that pure lily, is born from the disreputable Sidonie, in the rapture which makes mystics or lovers, according to the environment. The three children of the Mourets are born of the same breath which makes of the clever Octave the dry goods merchant, a millionaire; of the devout Serge, a poor country priest; of the imbecile Désirée, a beautiful and happy girl. But the example is still more striking in the children of Gervaise; the neurosis passes down, and Nana sells herself; Étienne is a rebel; Jacques, a murderer; Claude, a genius; while Pauline, their cousin german, near by, is victorious virtue—virtue which struggles and immolates itself. It is heredity, life itself which makes imbeciles, madmen, criminals and great men. Cells abort, others take their place, and we have a scoundrel or a madman instead of a man of genius, or simply an honest man. And humanity rolls on, bearing everything on its tide.” Then in a new shifting of his thought, growing still more animated, he continued: “And animals—the beast that suffers and that loves, which is the rough sketch, as it were, of man—all the animals our brothers, that live our life, yes, I would have put them in the ark, I would give them a place among our family, show them continually mingling with us, completing our existence. I have known cats whose presence was the mysterious charm of the household; dogs that were adored, whose death was mourned, and left in the heart an inconsolable grief. I have known goats, cows, and asses of very great importance, and whose personality played such a part that their history ought to be written. And there is our Bonhomme, our poor old horse, that has served us for a quarter of a century. Do you not think that he has mingled his life with ours, and that henceforth he is one of the family? We have modified him, as he has influenced us a little; we shall end by being made in the same image, and this is so true that now, when I see him, half blind, with wandering gaze, his legs stiff with rheumatism, I kiss him on both cheeks as if he were a poor old relation who had fallen to my charge. Ah, animals, all creeping and crawling things, all creatures that lament, below man, how large a place in our sympathies it would be necessary to give them in a history of life!”