From the first dawn of life, all organic beings are found to resemble each other in descending degrees, so that they can be classed in groups under groups. This classification is evidently not arbitrary like the grouping of stars in constellations.
There is no fundamental difference between man and the higher mammals in their mental faculties. . . . The difference in mind between man and the higher animals, great as it is, certainly is one of degree and not of kind.
We have seen that the senses and intuitions, the various emotions and faculties, such as love, memory, attention and curiosity, imitation, reason, etc., of which man boasts, may be found in an incipient, or even sometimes in a well-developed condition, in the lower animals.