Johann Karl Friedrich Rosenkranz (April 23, 1805 – July 14, 1879) was a German philosopher and pedagogue.
Born in Magdeburg, he read philosophy at Berlin, Halle and Königsberg, devoting himself mainly to the doctrines of Hegel and Schleiermacher. After holding the chair of philosophy at Halle for two years, he became, in 1833, professor at the University of Königsberg. In his last years he was quite blind.
He died in Königsberg.
Throughout his long professorial career, and in all his numerous publications he remained, in spite of occasional deviations on particular points, loyal to the Hegelian tradition as a whole. In the great division of the Hegelian school, he, in company with Michelet and others, formed the "centre," midway between Erdmann and Gabler on the one hand, and the "extreme left" represented by Strauss, Feuerbach and Bruno Bauer.
- Kritik der Schleiermacherschen Glaubenslehre (1836)
- Psychologie oder Wissenschaft vom subjektiven Geist (1837; 3rd ed., 1863)
- Kritische Erläuterungen des Hegelschen Systems (1840)
- Vorlesungen über Schelling (1842)
- Hegels Leben (1844)
- System der Wissenschaft (1850)
- Meine Reform der Hegelschen Philosophie (1852)
- Ästhetik des Häßlichen" (Königsberg 1853). English: Aesthetics of Ugliness. A Critical Edition. Bloomsbury 2015.
- Wissenschaft der logischen Idee (1858–59), with a supplement (Epilegomena, 1862)
- Diderot's Leben und Werke (1866)
- Hegels Naturphilosophie und die Bearbeitung derselben durch Vera (1868)
- Hegel als deutscher Nationalphilosoph (1870)
- Erläuterungen zu Hegels Encyklopädie der philosophischen Wissenschaften (1871).
Between 1838 and 1840, Rosenkranz published an edition of the works of Kant in conjunction with F. W. Schubert, to which he appended a history of the Kantian doctrine.