The book Słowa jak ziarna. Reformacyjne idee, książki, spory [Words like seeds. Reformation ideas, books, disputes] deals with the Polish Protestant writings of the 16th and 17th centuries. It follows ideological changes and literary achievements of the mature but turbulent period of Polish Protestant Reformation – especially in its Antitrinitarian variety – defining the character of the whole Polish culture at that time. Part One (“Idee” [Ideas]) introduces three great issues: relation between humanitas and christianitas (in the model developed by the Polish Brethren), cultural aspects of formation and functioning in the 16th century of religious communities and the Protestant metalinguistic reflection. Part Two is devoted to three outstanding, yet unknown works of Protestant religious literature: Paweł Milejewski’s paraphrases of psalms (1587), Marcin Czechowic’s treatise Zwierściadłko (1582) and an Arian prayer book composed by Jan Stoiński (1633). In Part Three there are analysed different polemic and persuasive tools: gossip, untypical functions of Biblical writings and argumentum ad timorem in the Protestant spirituality.