If the philosopher can display a mass of knowledge of which the savage is ignorant, the savage can show to the philosopher that his mind in some things is more ignorant than his own. Both have used their senses; both have examined and reflected; both have accumulated a store of information, which they turn to account: but the savage cares only for that which enables him to enjoy animal existence. He, therefore, investigates the habits of the animals around him, and the nature of the plants; he tames some of the former, he cultivates some of the latter; he stores up provisions, he invents rude weapons; he builds kraals, or huts; he fashions boats, kajaks, or proas; he employs fire; and though he cannot discuss the laws of caloric, he knows many of them practically. In fact, his senses are to him the inlets of ideas, without any abstruse cogitation. He cannot but acquire knowledge through his senses, but he labours to acquire no more than is subservient to his present interest. To the philosopher, the senses are also the inlets of ideas; but then he is thereby led to abstruse cogitation, to experiments, and reiterations upon these, forming theories to be rejected or adopted, as laborious investigation may determine.
And wherefore?--Not contented with the vacuity of mere animal enjoyments, he antedates his spiritual existence, and while yet on earth soars to other worlds, or dives into the profound mysteries of nature. Between the rude savage and the philosopher there are innumerable gradations; yet the rude savage, if cultivated, might become the philosopher--and why?--Because, though mental powers, like bodily powers, differ, the mental anatomy, like the corporeal, is on the same plan; and, figuratively speaking, the muscles of the former may become by exercise as developed as the muscles of the latter. To what fields, then, of knowledge are the senses avenues--and avenues, because they are adapted to the condition of the globe we inhabit, and because the impressions which they receive are seized upon by the mind, being there alone made palpable; and because the mind, by a reflex action, thence derives ideas, and combines and analyzes them.
The higher animals possess the same senses as man; and, it may be asked, Why do they not gain a similar knowledge to that which man acquires? We have already said, that the higher animals possess something which cannot but be termed mind, since they have passions and affections, memory, etc., which are qualities of mind, and not of matter. But, then, their mind is not only inferior in degree to that of man, but different in its anatomical construction. Certain animals, moreover, are inferior to others, and among animals of the same species there are different degrees of mental as well as of bodily force. Here, however, we can only generalize. Let it suffice, then, that we adduce for the purpose of illustration an animal with which we are all familiar--a domesticated animal, capable of a high degree of education, and which man has trained to the most various and opposite purposes--we allude to that attached servant of our race, the dog. Let it stand as a type of the higher quadrupeds.