After completing his education at St. Afra's, he enrolled at Leipzig University where he pursued a degree in theology, medicine, philosophy, and philology (1746–1748).

In 1750, Lessing and Mylius teamed together to begin a periodical publication named Beiträge zur Historie und Aufnahme des Theaters.

From 1760 to 1765, he worked in Breslau (now Wrocław) as secretary to General Tauentzien during the Seven Years' War between Britain and France, which had effects in Europe.

Actor-manager Konrad Ackermann began construction of Germany's first permanent national theatre in Hamburg, established by Johann Friedrich Löwen [de].

Follower of Spinoza's philosophy,[5] on 14 October 1771, Lessing was initiated into Freemasonry in the lodge "Zu den drei Goldenen Rosen" in Hamburg.

[6] In 1773, he discovered Archimedes' cattle problem in a Greek manuscript containing a poem of 44 lines, in the Herzog August Library in Wolfenbüttel.

A 2003 biography of Mendelssohn's grandson, Felix, describes their friendship as one of the most "illuminating metaphors [for] the clarion call of the Enlightenment for religious tolerance".

Scholars see Miss Sara Sampson and Emilia Galotti as amongst the first bourgeois tragedies, Minna von Barnhelm (Minna of Barnhelm) as the model for many classic German comedies, Nathan the Wise (Nathan der Weise) as the first German drama of ideas ("Ideendrama").

He argued against the belief in revelation and the holding on to a literal interpretation of the Bible by the predominant orthodox doctrine through a problem later to be called Lessing's Ditch.

Despite discouragement from his brother Karl Gotthelf Lessing, he began publishing pieces of the manuscript in pamphlets known as Fragments from an Unnamed Author.

In concern for tarnishing his reputation, Goeze requested the government put an end to the feud, and Lessing was silenced through a law that took away his freedom from censorship.

[13] In response, Lessing relied upon his skills as a playwright to write what is undoubtedly his most influential play, Nathan the Wise.

In the play, Lessing set up tension between Judaism, Islam, and Christianity by having one character ask Nathan which religion was the most genuine.

The Enlightenment ideas to which Lessing held tight were portrayed through his "ideal of humanity," stating that religion is relative to the individual's ability to reason.

The idea of freedom (for the theatre against the dominance of its French model; for religion from the church's dogma) is his central theme throughout his life.

[citation needed] Lessing is important as a literary critic for his work Laocoon: An Essay on the Limits of Painting and Poetry.

The Radical Pietist Johann Daniel Müller [de] (born 1716 in Wissenbach/Nassau, today part of Eschenburg, deceased after 1785) published the following anonymous book against Lessing and Reimarus: