German physician and lecturer on philosophy; born June 17, 1747, at Berlin; died there Jan. 19, 1803. The son of very poor parents, he was destined for a mercantile career, and in 1762 went to Königsberg, East Prussia. He soon gave up his position as clerk and attended the university, becoming a pupil of Kant, but was obliged to discontinue his studies for want of means. He thereupon became secretary to the wealthy Russian Ephraim, traveling with him through the Baltic Provinces. In 1770 he returned to Germany and studied medicine in Halle, where he became an M.D. in 1774, in which year he established himself in Berlin, being appointed physician at the Jewish hospital. In 1777 he commenced to deliver public lectures on medicine and philosophy, which were well attended by the students and the principal personages of the Prussian capital. At some of them even members of the royal family were present.
Herz married in 1779 Henriette de Lemos (see Henriette Herz); and their house was for a long time the rendezvous of Berlin's political, artistic, and literary celebrities. In 1782 he became ill through overstudy, and had to give up his lectures till 1785, when a sojourn in Pyrmont restored his health. In 1791 he received the title of professor of philosophy at the academy and that of "Hofrath," but lectured only a few years, giving most of his time to his medical practise. Herz was a friend and pupil of Moses Mendelssohn, and was also well acquainted with Lessing.
Herz was the author of: "Betrachtungen aus der Spekulativen Weltweisheit," Königsberg, 1771; "Freimüthige Kaffeegespräche Zweier Jüdischer Zuschauerinnen über den Juden Pinkus," Berlin, 1772, a satirical essay; "Versuch über die Ursachen der Verschiedenheit des Geschmacks," Mitau, 1776; "Briefe an Aerzte," Berlin, 1777-84; "Grundriss der Medizinischen Wissenschaften," ib. 1782; "Versuch über den Schwindel," ib. 1786, 2d ed. 1791, an important study; "Grundlage zu den Vorlesungen über die Experimental-Physik," ib. 1787; "Ein Sendschreiben an die Redaktion der Meassefim über das zu Frühe Beerdigen der Todten bei den Juden," ib. 1789.
Compulsory vaccination was strongly condemned by Herz, and in 1801 he wrote an open letter on the subject to Dr. Dohmeyer, under the heading "Ueber die Brutalimpfung."
- R. J. Wunderbar, in Der Orient, Leipsic, June 30, 1849, pp. 408 et seq.;
- Ludwig Geiger, in Allg. Deutsche Biographie, 1880, xii. 261 et seq.;
- Oesterreichische Wochenschrift, Jan. 23, 1903, p. 59;
- Hirsch, Biog. Lex.