The physiology of the human body examines the unique characteristics and mechanisms that make the human body a living being. The very fact that we remain alive almost surpasses our control, as hunger forces us to seek food and fear drives us to find shelter.

The sensation of cold prompts us to take care to warm ourselves, and other forces compel us to seek companionship and reproduce. Therefore, humans are essentially automatic beings, and the fact that we have feelings, emotions, and knowledge is part of this automated sequence of life; these special abilities allow us to exist under very different conditions which would otherwise make life impossible.

[Excerpt from the text of the preface]