Moritz Lazarus (15 September 1824 – 13 April 1903), born at Filehne, in the Grand Duchy of Posen, was a German-Jewish philosopher, psychologist, and a vocal opponent of the antisemitism of his time.

The son of Aaron Levin Lazarus, a pupil of Akiba Eiger, and himself president of the bet din and the yeshiva of Filehne (died there in 1874), he was educated in Hebrew literature and history, and subsequently in law and philosophy at the University of Berlin.

The psychologist must study mankind from the historical or comparative standpoint, analysing the elements which constitute the fabric of society, with its customs, its conventions and the main tendencies of its evolution.

This Völkerpsychologie (folk or comparative psychology) is one of the chief developments of the Herbartian theory of philosophy; it is a protest not only against the so-called scientific standpoint of natural philosophers, but also against the individualism of the positivists.

In an article entitled "Ueber den Begriff und die Möglichkeit einer Völkerpsychologie als Wissenschaft" (in Robert Prutz's "Deutsches Museum," 1851) he laid the foundation for the study of this science.

Nine years later, in collaboration with Steinthal, his friend and brother-in-law, Lazarus established the "Zeitschrift für Völkerpsychologie und Sprachwissenschaft" (vols.

In 1895 Lazarus, after the death of his first wife, married the widow Nahida Ruth Remy, who was raised a Protestant[1] but under his influence had embraced Judaism.

His most important lectures on Jews and Judaism were collected and published in his "Treu und Frei," Leipzig, 1887 (containing his speeches at the meetings of the two synods; "Was Heiss National?

Like many of his contemporaries, he believed (erroneously) that antisemitism was merely a passing fancy, a phenomenon engendered by reactionary times, which could be explained away in writings or addresses.

Much cited for apologetic purposes is his definition of the concept "nation," as the essential and only objective characteristic of which he takes not the similarity of customs and morals, of territory, religion, and race, but the bond of language.