The paper is a mathematical and philosophical essay devoted to mathematical logic school created and guided by Andrzej Mostowski. Firstly, we discuss some of the main—still actual—achievements of Andrzej Mostowski, then we discuss weak sides of his scientific project. They are computational and philosophical.Scientific challenges of our times in logic are mainly computational. The Warsaw school of mathematical logic did not support this direction.Partially because of the political situation in Poland public philosophical discussions were strongly influenced by hard politics, including personal politics in academic institutions. Therefore, many people think that isolation of the foundations of mathematics and philosophy was forced by the communist ideology. This impression is false. The abyss between philosophy and the foundations was basically independent of the political situation in Poland.What can we learn from this experience?