Considerations of a practical nature give us the most possible grounds for a belief that human desires, feelings, etc., are homogeneous and communicable. The fact is that we all have back of us many millions of years of evolutionary history in the same general environment. In the past, with relatively minor , the same influences have played upon our ancestors from the beginnings of life on our planet. And then, we are born into the same society, and it has given us, not, to be sure, the power of , but certainly all of our most essential stimuli. Further, we do get along in society. We laugh together, and we play together, we share each other's sorrows, we love and hate each other, in a way that would be wholly impossible if we did not in practice the correctness of our 'inferences' about one another's motives and desires. And the fact that these 'inferences' are in the main correct is the one thing that makes social life possible. We can, and do, understand one another's motives, desires, wants, emotions. We can, and do, communicate our feelings to one another.