I, on the contrary, maintain that we are never entitled to raise into a genus that which we only know of in a single species. For we could bring nothing into our idea of the genus but what we had abstracted from this one species; so that what we should predicate of the genus could after all only be understood of the single species.

While, if we should attempt to think away (without any warrant) the particular attributes of the species, in order to form our genus, we should perhaps remove the exact condition whereby the remaining attributes, hypostatised as a genus, are made possible. Just as we recognise intelligence in general to be an attribute of animal beings alone, and are therefore never justified in thinking of it as existing outside, and independent, of animal nature; so we recognise Reason as the