This letter, written by Ladislav Hejdánek on November 16, 1971, is addressed to his family from prison. The author begins with warm greetings and inquiries about the daily lives and academic progress of his daughters. A significant portion of the text is a philosophical reflection dedicated to his daughter Jana on her fifteenth birthday. Hejdánek elaborates on the concept of the "discovery of the future," arguing that past events are not immutable but can be reinterpreted and given new meaning through one's subsequent life choices. He encourages Jana to remain open to the truth and to serve as a pillar of support for her mother and sisters. The final section contains practical requests for books—specifically Hegel’s History of Philosophy and an English textbook—stationery, money, and food. The letter provides a poignant insight into the intersection of paternal care, philosophical resilience, and the constraints of political imprisonment during the normalization era in Czechoslovakia.