He explains it here. But if you don't want to click, here's what he said:  Blank slate: "at birth the (human) mind is a "blank slate" without rules for processing data, and that data is added and rules for processing are formed solely by one's sensory experiences.". Blank slatist is a person who believes humans are blank slates and blank slatism is the term for an individual who believes the term. Got it? Good.