The Historical Meaning of the Crisis in Psychology: A Methodological Investigation

To try and explain everything means to explain nothing.

Vygotsky, Lev. Marxists.org (1927). Books>Rhetoric>Theory

Thinking and Speaking

This book is a study of one of the most complex problems of psychology, the interrelation of thought and language. As far as we know, it has not yet been investigated experimentally in a systematic fashion. We have attempted at least a first approach to this task by conducting experimental studies of a number of separate aspects of the total problem.

Vygotsky, Lev. Marxists.org (1934). Books>Language>Theory