Johanna Charlotte Unzer, née Ziegler, was born in Halle on 27 November 1725 to Anna Elisabeth Ziegler (née Krüger, 1699–1751) and Johann Gotthilf Ziegler (1687/8–1747, a student of Bach’s) and died in Altona on 29 January 1782. As poet laureate of the University of Helmstedt, she was one of the few female thinkers allowed to speak publically. Her Grundriss einer Weltweisheit für das Frauenzimmer (1751) is a survey of philosophy for female readers. She described Leibniz-Wolffian tenets, while arguing for a philosophical anthropology that was well ahead of its time. Thus she defended the embodiment of consciousness, the fundamental similarity of animals and humans, and the metaphysical possibility of reincarnation. An early pioneer of environmental philosophy and a subtle critic of Christian theology, she could be characterized as a predecessor of Merleau-Ponty’s phenomenology of perception. Ranking among the most innovative philosophers of the century, her male peers dismissed her.
Her upbringing was guided by the pietist tenets of August Hermann Francke . Because her father was a church organist and piano teacher, students and scholars frequented the house. As a woman, Johanna was barred from college and depended on tutorials from guests and relatives. Georg Friedrich Meier , who acquainted Johanna with his discipline, was a regular visitor. Her uncle Johann Gottlob Krüger , a professor of medicine, further encouraged her. He was one of the Hallensian ‘Psychomediziner’ working on psychology and anthropology, and his earthy common-sense views influenced hers. One of Krüger’s assistants (who took music lessons with Unzer’s father) was Johann August Unzer . Unzer specialized in ‘Psychomedizin’ (Neue Lehre von den Gemüthsbewegungen, 1746) and became Johanna’s final mentor. In 1751, she married Unzer and moved to Altona, which enjoyed the liberal influence of nearby Denmark, where the couple founded a literary circle. In the same year, she published Grundriss einer Weltweisheit and Grundriss einer Naturlehre, enjoyed success with her poems, and suffered the loss of her mother (December 1751). Only her lyrics earned her recognition. Later, burdened by domestic duties, she wrote poems occasionally and turned to religion.
The Grundriss einer Weltweisheit deals with logic (§§ 17–131) and metaphysics (§§ 132–358). It contains chapters on ontology, cosmology, psychology and rational theology. A chapter on natural philosophy was published separately (Grundriss einer Naturlehre, 1751). Unzer is a masterful stylist. Her clarity, eloquence, and knack for the mot juste reveal her to be an exceptional writer. Her thought pushes the Spinozist envelope. One theme is the significance of light and fire (e.g., §§ 1, 80, 92–5); another is the affinity of humans and animals (e.g., §§ 106, 189, 246, 313–14). She argues that the soul is the representational force of the body (§ 242), and that representation is a conscious sensation constitutive of human and animal souls (§ 21). In the section ‘On the Souls of Animals’ (§ 322), Unzer discusses animal consciousness and deconstructs the problem of other minds just as environmental philosophers such as P. Singer do nowadays. Because sentient embodiment permits souls to represent and thus to engage with reality, the claim of non-corporeal souls requires qualification. Unzer interprets biblical resurrection as a renewed embodiment (§ 319) which involves reincarnation (‘Seelenwanderung’) and may occur in animals (‘thierische Verwandlung’). To pre-empt her critics, she points out that everything depends on prior causes (§§ 203, 215), infers that creation is distinct from its creator (§§ 215, 222) and objects to the Spinozist equation of nature and God (§ 334). A poem concludes her work; ‘just do not call me a heretic’, she urges the reader in the final verse.
Grundriss einer Weltweisheit für das Frauenzimmer, mit Anmerckungen und einer Vorrede begleitet, von Johann Gottlob Krügern (Halle, 1751); 2nd exp. edn, 1767, with Grundriss einer natürlichen Historie, repr. (Aachen, 1995).