The realization that our mental functioning is largely irrational was arrived at by several thinkers at the same time, including Friedrich Nietzsche... Freud, who was much influenced by both Darwin and Nietzsche... was its most profound and articulate exponent. ...Schnitzler, Klimt, Kokoschka, and Schiele also discovered and explored new aspects of our unconscious mental life. They understood women better than Freud... and they saw more clearly than Freud the importance of an infant's bonding to its mother. They even realized the significance of the aggressive instinct earlier than Freud did. ...Plato discussed unconscious knowledge ...pointing out that much of our knowledge is inherent in the psyche in latent form. ...Hermann von Helmholtz... advanced the idea that the unconscious plays a critical role in human visual perception.