 Christian Thomasius was born on 1 January 1655 in Leipzig. He was the son of Jakob Thomasius (1622–84), a well-known jurist and philosopher at the University of Leipzig who counted Leibniz among his students. Christian (hereafter simply ‘Thomasius’) matriculated in the philosophy faculty at Leipzig in 1669, and was promoted to Magister artium in 1672. As a result of his father’s lectures, particularly on Hugo Grotius’ De jure belli ac pacis, and his interest in Samuel Pufendorf’s De jure naturae et gentium, Thomasius took up the study of law in Frankfurt an der Oder in 1675 and was awarded a doctorate in 1679. After a brief journey to Holland, Thomasius returned to Leipzig where he worked (unhappily) as a lawyer while also holding private lectures on natural jurisprudence. Thomasius attests to the fundamental reorientation of his thinking effected by his reading of Pufendorf, and the Apologia pro se et suo libro (1674) in particular, which he credits for convincing him of the independence of natural law from theology as well as of the need to question authority and resist religious intolerance (Thomasius 1688a, “Diss. Proem.” §§5–10; Hochstrasser 2000: 113–121). This new anti-authoritarian cast of mind is clearly evident in a dissertation on bigamy of 1685, in which Thomasius defends the practice as consistent with natural law, and which unsurprisingly led to a confrontation with a professor in the theology faculty at Leipzig. Thomasius’ pioneering decision to hold lectures in German, announced (in German) in 1687, likewise provoked controversy, as did his publication beginning in 1688 of a monthly journal (the first periodical published in German), entitled the Monatsgespräche, in which Thomasius commented, frequently satirically, on the local intellectual scene. Thomasius’ lectures and publications increasingly generated conflict with the theological faculty in Leipzig, which upheld a rather strict form of Lutheran orthodoxy, and while his connections with the Saxon court stood him in good stead for a time, his defence of an inter-faith marriage involving a (Lutheran) Saxon count and a (Calvinist) Brandenburg princess cost him his protection, and in March 1690 he was prohibited from publishing and holding lectures (private and academic) in Electoral Saxony.