"The first type of abstraction from objects I shall refer to as simple abstraction, but the second type I shall call reflective abstraction, using this term in a double sense"
"Our problem, from the point of view of psychology and from the point of view of genetic epistemology, is to explain how the transition is made from a lower level of knowledge to a level that is judged to be higher"
"It is with children that we have the best chance of studying the development of logical knowledge, mathematical knowledge, physical knowledge, and so forth"
"In other words, knowledge of the external world begins with an immediate utilisation of things, whereas knowledge of self is stopped by this purely practical and utilitarian contact"
"Whitney wanted to eradicate the idea that in the case of a language we are dealing with a natural faculty; in fact, social institutions stand opposed to natural institutions"
"Medicine is not only a science; it is also an art. It does not consist of compounding pills and plasters; it deals with the very processes of life, which must be understood before they may be guided"
"For one country is different from another; its earth is different, as are its stones, wines, bread, meat, and everything that grows and thrives in a specific region"
"Any psychology of sign systems will be part of social psychology - that is to say, will be exclusively social; it will involve the same psychology as is applicable in the case of languages"
"The critical principle demanded an examination, for instance, of the contribution of different periods, thus to some extent embarking on historical linguistics"
"In general, the philological movement opened up countless sources relevant to linguistic issues, treating them in quite a different spirit from traditional grammar; for instance, the study of inscriptions and their language. But not yet in the spirit of linguistics"
"Every time I took a long leave from home, I felt as if I were going to conquer the world. Or rather, take possession of what is my birthright, my inheritance"
"The very special place that a language occupies among institutions is undeniable, but there is much more to be said-, a comparison would tend rather to bring out the differences"
