Although each of us is unique there is no one who could not be substituted. We can usually agree with this statement although sometimes we accept that there are exceptional individuals, though it is regretful that we do not encounter them frequently. There are people whose contribution to the life of a social group or an institution is diffi cult to replace. They integrate the group, motivate the group’s members to work better, offer a good example, willingly advise and help others, represent the ambitions of the group well, and so on. In the Poznań circle of political scientists Professor Czesław Mojsiewicz was such a fi gure. He had a tremendous infl uence on the profi le of this circle over the forty-two years of its active creation and shaping.