How socio-economic and cultural-historical conditions affect the development of science; the evolution of research methods, scientific discussions? What are the ways to form a scientific theory? A researcher of the history of science, corresponding member of the USSR Academy of Sciences S. R. Mikulinsky, answers these and other questions in his essays. The book highlights the views of V. I. Vernadsky, A. Dekandol, T. I. Rainov and others on the development of science.