KAHNIS, KARL FRIEDRICH AUGUST (1814-1888), German Lutheran theologian, was born at Greiz on the 22nd of December 1814. He studied at Halle, and in 1850 was appointed professor ordinarius at Leipzig. Ten years later he was made canon of Meissen. He retired in 1886, and died on the 20th of June 1888 at Leipzig. Kahnis was at first a neo-Lutheran, blessed by E. W. Hengstenberg and his pietistic friends. He then attached himself to the Old Lutheran party, interpreting Lutheranism in a broad and liberal spirit and showing some appreciation of rationalism. His _Lutherische Dogmatik, historisch-genetisch dargestellt_ (3 vols., 1861-1868; 2nd ed. in 2 vols., 1874-1875), by making concessions to modern criticism, by spiritualizing and adapting the old dogmas, by attacking the idea of an infallible canon of Scripture and the conventional theory of inspiration, by laying stress on the human side of Scripture and insisting on the progressive character of revelation, brought him into conflict with his former friends. A. W. Diekhoff, Franz Delitzsch (_Fur und wider Kahnis_, 1863) and Hengstenberg (_Evangelische Kirchenzeitung_, 1862) protested loudly against the heresy, and Kahnis replied to Hengstenberg in a vigorous pamphlet, _Zeugniss fur die Grundwahrheiten des Protestantismus gegen Dr Hengstenberg_ (1862). Other works by Kahnis are _Lehre vom Abendmahl_ (1851), _Der innere Gang des deutschen Protestantismus seit Mitte des vorigen Jahrhunderts_ (1854; 3rd ed. in 2 vols., 1874; Eng. trans., 1856); _Christentum und Luthertum_ (1871); _Geschichte der deutschen Reformation_, vol. i. (1872); _Der Gang der Kirche in Lebensbildern_ (1881, &c.); and _Uber das Verhaltnis der alten Philosophie zum Christentum_ (1884).