George John Romanes fut le disciple de Charles Darwin. A la demande de ce dernier, il fera l'application de la théorie sélective à l'évolution mentale et soutient que la différence entre les animaux et l'homme n'est que de degré et non de nature. Il défend l'hypothèse qu'avec l'homme aucune faculté mentale nouvelle n'est apparue; il n'y a qu'un accroissement en degré de facultés déjà manifestes chez l'animal. Il n'y a pas entre l'instinct et la raison une si grande différence.
In all places of the civilized world, and in all classes, the struggle for existence is now more keen than ever it has been during the history. Everywhere men, and women, and children are living at a pressure positively frightful to contemplate. Amid the swarming bustle of our smoke-smothered towns, surrounded by their zone of poisoned trees, amid the whirling roar of machinery, the scorching blast of furnaces, and in the tallow-lighted blackness of our mines-everywhere, men, and women, and children are struggling for life. Even our smiling landscapes support as the sons of their soil a new generation, to whom the freedom of gladness is a tradition of the past, and on whose brows is stamped, not only the print of honest work, but a new and sadding mark-the brand of sickening care. Or if we look to our universities and schools, to our professional men and men of business, we see this same fierce battle rage-ruined health and shattered hopes, tearful lives and early deaths being everywhere the bitter lot of millions who toil, and strive, and love, and bleed their young hearts' blood in sorrow. In such a world and at such a time, when more truly than ever it may be said that the whole creation groans in pain and travail, I do not know that for the purposes of health and happiness there is any subject which it is more desirable that persons of all classes should understand than the philosophical theory and the rational practice of recreation. For recreation is the great relief from the pressure of life - the breathing-space in the daily struggle for existence, without which no one of the combatants could long survive; and therefore it becomes of the first importance that the science and the philosophy of such relief should be generally known. No doubt it is true that people will always be compelled to take recreation and to profit by its use, whether or not they are acquainted with its science and its philosophy; but there can be equally little doubt that here, as elsewhere, an intelligent understanding of abstract principles as well as of practical applications will insure more use and less abuse of the thing which is thus intelligently understood...
This book deals with the phenomena of Animal Intelligence.
No phenomena in nature are watched with more interest by all classes, young and old, ignorant and educated, than the displays of intelligence in the inferior animals. From the dog, which occupies a position of intelligent companionship with man, down through the less favored species even to the lowest groups of animal life, we see manifested all degrees of that wonderful attribute which in its highest perfection constitutes the human mind.