Miftâh as-sa‘âde (“Key to happiness”) became very popular; its translation to Ottoman Turkish by his son, Kemalüddin Mehmed Efendi, under the title Mevzu’ât al-‘ulûm (“Subjects of the sciences”) had great success; Kâtib Çelebi’s bibliographic encyclopedia (the Keşf al-zünûn) was compiled along Taşköprüzade’s lines.
As for his encyclopaedia, Miftâh al-sa’âda wa misbâh al-siyâda fî mawzû’ât al-‘ulûm (“The key to happiness and the guide to nobility in the objects of science”), has this science as part of his section on ethics, and the books he enumerates are pseudo-Aristotle, al-Farabi, Tusi and Devvani. Taşköprüzade comments that “the science of government is the knowledge of what state and government entail, the condition of dignitaries, the situation of subjects and the welfare of cities. This is a science which rulers need first, and then other people. Because man is by nature social. A person is required to reside in a virtuous city (al-madînatü’l-fâdıla) and migrate from an unvirtuous one, and to know how the residents of the virtuous city could benefit from him and how he could benefit from them” (Taşköprüzade – Bakry – Abu’l-Nur 1968, 1: 407-8, as translated by Yılmaz 2005, 8). Apart from the “science of government (siyasa)”, there are also sections on practical wisdom, manners for kings (âdâb al-mulûk) and viziers (âdâb al-wizâra), market inspection (ihtisâb), military administration, and so forth.