Fa. Yes—they have all four cutting teeth in the upper jaw, and teats on the breast. How do your like your relations?
Ch. Not at all!
Fa. Then we will get rid of them by applying to the other part of human nature—the mind. Man is an animal possessed of reason, and the only one. This, therefore, is enough to define him.
Ch. I have often heard that man is a rational creature, and I have a notion what that means; but I should like to have an exact definition of reason.
Fa. Reason is the faculty by which we compare ideas, and draw conclusions. A man walking in the woods of an unknown country finds a bow. He compares it in his mind with other bows, and forms the conclusion that it must have been made by man, and that therefore the country is probably inhabited. He discovers a hut; sees in it half-burnt wood, and finds that the ashes are not quite cold. He concludes, therefore, with certainty, not only that there are inhabitants, but that they cannot be far distant. No other animal could do this.
Ch. But would not a dog who had been used to live with men run into such a hut and expect to find people in it?
Fa. He probably would—and this, I acknowledge, is very like reason; for he may be supposed to compare in his mind the hut he has lived in with that he sees, and to conclude that as there were men in the first there are in the last. But how little a way does this carry him? He finds no men there, and he is unable by any marks to form any judgment how long they have been absent, or what sort of people they were; still less does he form any plan of conduct in consequence of his discovery.
Ch. Then is not the difference only that man has much reason, and brutes little?
Fa. If we adhere to the mere words of the definition of reason, I believe this must be admitted; but in the exercise of it, the superiority of the human faculties is so great, that man is in many points absolutely distinguished from brutes. In the first place he has the use of speech, which no other animal has attained.
Ch. Cannot many animals make themselves understood by one another by their cries?