The article deals with the formation of the views of one of the prominent lawyers of the 19-20 centuries, the founder of legal realism in the science of constitutional law, an Associate Justice of the Supreme Court of the United States Oliver Wendell Holmes. The importance of judicial decisions taken by Holmes, including dissenting opinions, as well as their impact on the historical development of the country and the Common law in general, occupies an important place in the world of legal science. In this regard, it is especially important to identify and study those starting points that have become the basis for the formation of his views, both moral and philosophical. There are three main periods in the life of Oliver Wendell Holmes, which significantly influenced the formation of his worldview and the formation of his moral and philosophical views. First, it is childhood and youth, which took place in a Puritan family. The ideas of this doctrine became the cornerstone in the formation of his personality. Secondly, it is active participation in the Civil war, which in some sense turned his mind, sharpened feelings and honed a unique view of many issues. And finally, studying in higher education, familiarity with legal science and awareness of the scarcity and lack of accumulated theoretical knowledge of common law, his contact with the actual dogmas adopted in law, all this has served as a new impetus for the final formation of his moral and philosophical approach in the future to the solution of Court cases.
In the framework of this writing the authors used the following methods: historical and genetic method (in the study of biographical data) and analytical method to identify the stages of formation of moral and philosophical views of O. W. Holmes.