M. Weber is criticized by many philosophers, such as A. Macintyre or M. Horkheimer, for his concept of instrumental rationality which was seen as one of the sources of contemporary emotivism. The limited understanding of the social role of scientists, which is reduced to a clarification of relations between facts, an imperative to abstain from a defense of any particular form of ideology is considered by such critics as a rejection from a possibility of a reasonable foundation of politics and morals. Although this interpretation is based on Weber’s texts, our interpretation of his speech «Science as a Vocation» allows us to avoid such conclusions and demonstrates not only the ethical importance of science but also the perspectives for ethics of science. We start with a brief discussion of emotivism, then we move to the analysis of Weber’s critiques, what we mentioned and finally, we analyze «moral achievement» of a scientist. Although science cannot justify any world views or values, it still makes its contribution to the moral domain by clarifying the necessary connections between certain purposes and means required to achieve them. Ethics of science could accomplish the same task but in relation to science itself, i.e. showing the possibly unwanted outcomes of scientific researches to let scientists decide whether they still want to accomplish them.