About Deaf-Blindness > What is Deaf-Blindness. Deaf-blindness is a low incidence disability and within this very small group of children there is great variability. Many children who are deaf-blind have some usable vision and/or hearing. The majority of children who are deaf-blind also have additional physical, medical and/or cognitive problems.
Introduction-David Hume. The Philosopher David Hume is famous for making us realize that until we know the Necessary Connection / cause of things then all human knowledge is uncertain, merely a habit of thinking based upon repeated observation (induction), and which depends upon the future being like the past.
David Hume (1711-1776) was a positivist. He wanted to infer causality based on observed high correlations between events. Today, every introductory psychology student is taught to reject the notion that a correlation between events, even a very high correlation, is proof of causation.