There is a profound, inescapable need for animals that is in all people everywhere, an urgent requirement for which no substitute exists. It is no vague, romantic, or intangible yearning, no simple sop to our loneliness for Paradise. It is as hard and unavoidable as the compounds of our inner chemistry. It is universal but poorly recognized. It is the peculiar way that animals are used in the growth and development of the human person, in those most priceless qualities which we lump together as “mind” . . . Animals are among the first inhabitants of the mind’s eye. They are basic to the development of speech and thought. Because of their part in the growth of consciousness, they are inseparable from a series of events in each human life, indispensable to our becoming human in the fullest sense.
Paul Shepard, Thinking Animals