He also formulated the concept of the Zone of Proximal Development.  
This author noted that deafness was worse than blindness in a social world in a work on disabilities titled The Fundamental Problems of Defectology.  This man addressed the "Gentle Breath" of Ivan Bunin and adopted Tolstoy's approach to dealing with the enigma of Hamlet without the weight of commentary in sections from his Psychology of Art.  He asserted that (*) learning depended on someone with greater knowledge in a subject than the person being taught in his concept of the More Knowledgeable Other.  He begins one of his best known works with an examination of the theories of Piaget and Stern before building to "the Development of Scientific Concepts in Childhood".  He also formulated the concept of the Zone of Proximal Development.  For 10 points, name this author of Thought and Language, a Soviet psychologist.
This author noted that deafness was worse than blindness in a social world in a work on disabilities titled The Fundamental Problems of Defectology.  
Lev Semyonovich {Vygotsky}