Similar to psychoanalysis, I have examined the subjective experience of the most severe psychiatric illnesses, but I have interpreted them in the context of our species’ evolution instead of childhood development. The distortions of normal mental function in sufferers of mental illness magnify emotions and motivations so elemental that they can be pieced together into a narrative of the inner experience of human evolution. Two forms of major depression reflect the rise of social fears in apes some 50 million years ago, and schizophrenia disables the collective system of communication likely to have appeared with our ancestral species. The manic phase of bipolar disorder is linked by pathology in cognitively demanding speech to motivations that distinguish our own species. The essay humanizes the scientized fields of psychiatry and human evolution with emotions and motivations that we all know intimately. My mission is to treat the abiding stigma of mental illnesses by identifying their disturbing symptoms as emotional fossils that illuminate our evolutionary journey.