From 1802 to 1805, the poet Goethe visited Reil to discuss scientific matters such as psychiatry and to access his skills as a physician.

[3] Reil used the term 'Psychiaterie' in a short-lived journal he set up with J.C. Hoffbauer, titled Beyträge zur Beförderung einer Kurmethode auf psychischem Wege (1808: 169).

He saw this as due not to physical lesions in the brain or to hereditary evil, but as a disturbance in the harmony of the mind's functions (forms of awareness or presence), rooted in the nervous system.

[10] Reil also wrote on Blumenbach's idea of the Bildungstrieb (literally, "building power"), a vital force within each organism that compels it to create, maintain, and repair its form.

In Reil's essay "Von der Lebenskraft," he argued that each organism contained a "dormant germ" that was activated by the addition of the father's "animal force.