This chapter discusses the nature of subcortical brain systems that are being revealed by research on other animals. It provides a scientifically based vision about the origins of mind. Although neuroscientists have long known much about the ancient emotional circuits of brains, these circuits have only recently been definitively linked to emotional feelings. This allows neuroscientists to delve deeply into the neural substrates of affects—the menagerie of basic internally generated feelings. The detailed knowledge of modern neuroscience, gleaned largely from animal research, has revealed that it is no longer useful to distinguish between the mind and the brain. There are few neuroscientists and even fewer psychologists who are working on how primary-process emotional mechanisms, shared by all mammals, are constituted in the brain. Many emotion researchers as well as neuroscience colleagues make a sharp distinction between affect and emotion, seeing emotion as purely behavioral and physiological responses that are devoid of affective experience.