2012 Reprint of 1926 American Edition. Exact facsimile of the original edition not reproduced with Optical Recognition Software. Jean Piaget was one of the most salient and inspirational figures in psychological and educational research this century. He was a prolific authoring or editing over eighty books and numerous journal papers, which have spawned a huge and fertile continuation of his research over the decades. A major component of any course on children's psychological development and a research tradition that is expanding, scholars need access to the original texts rather than relying on secondhand accounts. Piaget wanted to revolutionize the way research methods were conducted. Although he started researching with his colleagues using a traditional method of data collection, he was not fully satisfied with the results and wanted to keep trying to find new ways of researching using a combination of data, which included: naturalistic observation, psychometrics, and the psychiatric clinical examination, in order to have a less guided form of research that would produce more genuine results. As Piaget developed new research methods, he wrote The Language and Thought of the Child , which aimed to synthesize the methods he was using in order to study the conclusions children drew from situations and how they arrived at such conclusions. The main idea was to observe how children responded and articulated certain situations with their own reasoning in order to examine their thought processes.