This research highlights on an important and fundamental issue of the 20th century's most
important philosophers, "Gaston Bachelard", which is the analytical approach to scientific
knowledge of this philosopher and the role played by "Gaston Bachel
ard" in this approach
in formulating a set of scientific concepts that enriched epistemology as the concept of the
epistemological obstacle ,The concept of estrangement and the concept of undo time, with
concentration on importance of the dialectical relationship between these concepts and
their role in the development of scientific knowledge.
