The article presents and analyzes the most important determinants of Josef Pieper’s thought form (»Denkform«). The first part of the paper examines the influence of Romano Guardini’s thought on the development of Pieper’s thought form. Particular attention is put on Guardini’s lecture on the classical spirit which Pieper had an opportunity to hear and which left a deep impression on him. Such an understanding of the classical spirit, together with the influence of the phenomenological thought, is the basic characteristic of Pieper’s thought form. The classical spirit, as a thought form, here means the insistence on the objective, on observing what is being given to us, as it is given to us. The second part of the paper seeks to broadly present, based on some texts of the German author, a thesis on the classical spirit as Josef Pieper’s thought form. The third part of the article shows and analyzes Pieper’s understanding of philosophy, leisure, and myths which he, in line with Guardini and the phenomenological approach, determines within the idea of the classical spirit. Part four is a critical review of Pieper’s thought form. Here, the absence of problematization of the practical mind (action) is seen as the basic lack of the same. Nevertheless, there is an emphasis on the great importance and the actuality of Josef Pieper’s thought, especially in the age of universal subjectivism, which is incapable of free, unobtrusive observation of the object, of all that is given.