Initially he studied theology at the University of Königsberg,[10] but became a clerk in a mercantile house and afterward held many small public offices, devoting his leisure to reading philosophy.

There, he underwent a profound Christian conversion, reorienting his whole life and philosophy around the prophetic illuminating power of the Bible.

[13] His translation of David Hume into German is considered by most scholars to be the one that Hamann's friend Immanuel Kant, also from Königsberg, credited with awakening him from his "dogmatic slumber".

[15] Hamann was a lutenist, having studied this instrument with Timofiy Bilohradsky (a student of Sylvius Leopold Weiss), a Ukrainian virtuoso then living in Königsberg.

His distrust of autonomous, disembodied reason and the Enlightenment ("I look upon logical proofs the way a well-bred girl looks upon a love letter" was one of his many witticisms) led him to conclude that faith in God was the only solution to the vexing problems of philosophy.

In Aesthetica in nuce, Hamann counters the Enlightenment by emphasizing the importance of aesthetic experience and the role of genius in intuiting nature.

Fragments of his writings were published by Cramer, under the title of Sibyllinische Blätter des Magus aus Norden (1819), and a complete edition by Roth (7 vols., 1821–25, with a volume of additions and explanations by Wiener, 1843).

Most recently, Hamann's influence can be found in the work of the theologians Oswald Bayer (Lutheran), John Milbank (Anglican), and David Bentley Hart (Eastern Orthodox).

However, recent scholarship, such as that by Bayer, contradicts the usual interpretation by people such as historian of ideas Isaiah Berlin, and describes Hamann as a "radical Enlightener" who vigorously opposed dogmatic rationalism in matters of philosophy and faith.

[21] Bayer views him as less the proto-Romantic that Herder presented, and more a premodern-postmodern thinker who brought the consequences of Lutheran theology to bear upon the burgeoning Enlightenment and especially in reaction to Kant.