This paper presents the main ideas of Feliks Mlynarski (1884 -1972), Polish politician and a fighter for National Independence who was also a philosopher, sociologist and a political thinker. In his writings he merged an approach to a nation as the main category of political thinking with a liberal conception of international order founded on free trade and international financial cooperation. It is an interesting example of Polish liberal nationalism, less well -known than the chauvinistic branch of the Polish national movement. In his philosophical works Mlynarski accepted the epistemological method of William James and mixed it with a Bergosonian concept. The greatest achievement of Mlynarski are his writings on international finance. In the monetary theory Mlynarski was a disciple of Irving Fisher. As a prolific writer on finance Mlynarski postulated the creation of a new international financial order that would replace ineffective gold (or gold- -exchange) standard. He believed that good functioning of international finance was fundamental for the West civilization with it main institutions: the nation state, representative government and civil liberty. Principally an advocate of the market economy, Mlynarski did not support the kind of capitalism dominated by big business and he spoke for reconstruction of economic system towards increasing the role of cooperatives in economy and distributing part of profits among factory workers.