Further, that dogs, if they possess ideas at all, have memories and expectations, and those potential beliefs of which these states are the foundation, can hardly be doubted by any one who is conversant with their ways.

Finally, there would appear to be no valid argument against the supposition that dogs form generic ideas of sensible objects.

One of the most curious peculiarities of the dog mind is its inherent snobbishness, shown by the regard paid to external respectability.

The dog who barks furiously at a beggar will let a well-dressed man pass him without opposition.

Has he not then a "generic idea" of rags and dirt associated with the idea of aversion, and that of sleek broadcloth associated with the idea of liking?
In short, it seems hard to assign any good reason for denying to the higher animals any mental state, or process, in which the employment of the vocal or visual symbols of which language is composed is not involved; and comparative psychology confirms the position in relation to the rest of the animal world assigned to man by comparative anatomy.
As comparative anatomy is easily able to show that, physically, man is but the last term of a long series of forms, which lead, by slow gradations, from the highest mammal to the almost formless speck of living protoplasm, which lies on the shadowy boundary between animal and vegetable life; so, comparative psychology, though but a young science, and far short of her elder sister's growth, points to the same conclusion.
In the absence of a distinct nervous system, we have no right to look for its product, consciousness; and, even in those forms of animal life in which the nervous apparatus has reached no higher degree of development, than that exhibited by the system of the spinal cord and the foundation of the brain in ourselves, the argument from analogy leaves the assumption of the existence of any form of consciousness unsupported.