The work of Milan Simecka (1930 - 1990) is known in Slovakia predominantly in connection with his activities of a secularly oriented dissent. From the perspective of a literary genre the attention of literary theorists and critics was drawn to his journalism and essayistic, in which his civic attitudes are reflected. Less attention was given to his epistolary - memoir works, where we can identify in significant presence of aesthetic moments. This is what the author of the study wants to stress. Simecka's 'Letters from the prison' (1999) are an object of interpretation.. He wrote them during politically motivated imprisonment in 1981-1982. Simecka's letters are marked by actual life situation - their author had to count with permanent presence of prison censorship and creates his own language and 'substitute' apolitical themes connected with his private life. That is why he works more with metonymy and metaphor and he is more 'artistic' than openly socially -critical, as it is visible in his journalistic and essayistic works from the 70th and 80th. The author of the study refers to the text of Peter Zajac 'Aesthetic as a Life Principal', where this aspect of the works of Simecka was correlated to European philosophical tradition. Thematic pendant to Simecka's letters a German protestant theologian Dietrich Bonhoeffer's letters from prison are shown 'On the Way To Freedom' and letters of Václav Havel, published as 'Letters to Olga'. The common experience in the extreme life situation made them connected. They result in the same reaction - creating an alternative reality differently structured from the true one behind the walls of their prison. The study reflects theoretic results of a Czech literary critic J. Lopatka, who in the 80th dealt with autobiographic genres. From the stylistic aspect the author of the study analyses Simecka's letters as a proto-text of 'erziehungsnovel', from the aspect aesthetics and of value he put him into wider Czecho-Slovak literary and philosophic context (V. Havel, L. Vaculik, D. Tatarka, I. Kadlecik, R. Sloboda, K. Kosik, J. Patocka, V. Belohradský). The author of the study compares a philosophical essay 'Letters about the Character of Reality', which is also included into these texts, with Bondy's 'Consolation from Ontology', which is a 'classical' work of Czech philosophical underground. He points out an ecologic measure of Simecka's opinions, rooted in the reforming Marxism of the 60th, as well as in the critic of technocratism in the works of representatives of the Frankfurt School.