He began an apprenticeship as a bookseller, but fell ill and turned in the self-study on various natural remedies, through which he became a lay practitioner. For a philosophy of medicine he most strongly advocated a "Return to Nature", utilizing natural food, clean water, fresh air, earthen clay, as well as time spent in nature itself. Eckertal in 1895 he founded the Naturopathic Institute Jungborn. The most prominent patient was Franz Kafka. In 1918 Just founded the healing clay Society in Blankenburg, and started the company, Luvos. His main work attracted interest in India and led there to set up a still existing natural medicine hospital in Pune. Just held a Christianized religious ideology based on the idea that salvation could be regained by understanding how primordial man used to live. He held the belief that in the beginning, "all creatures, frog and mouse, hedgehog and hare, deer, and elk, fox and badger" all lived in harmony with the Creator. Animals remained in their pristine state of grace, whilst man fell. He believed that by studying the behaviour of animals, people could experience salvation of the soul. Just believed that Jesus came to redeem humanity by teaching how to live in harmony with nature. His best known work Kehrt zur Natur zurück!, was translated by Benedict Lust in 1903. Just opposed everything that was not in accordance with nature. He opposed automobiles, modern housing and chemical agriculture. He rejected medical science and criticized vaccination and vivisection. He believed that vaccines were poisons that inflict misery upon people. Just advocated morning fasts and a raw foodvegetarian diet of unprocessed foods. He considered a diet of fruit and nuts to be the bestnatural foods for man. He rejected the use of any drugs but was also critical of homeopathy and gymnastics which he considered artificial. He commented that "to the physical culturists, therefore, I would say 'Return to Nature!' Come forth from your musty, dusty rooms and halls, out into free nature." Science writerMartin Gardner has noted that "Just's Return to Nature recommended sleeping on bare ground, walking barefooted on wet lawns and sand, and using clay compresses."
Publications
Jungborn echo. Brief History of Jungborn especially interesting judgments, reports, articles and important Kurberichte
The Jungborn - table. A new, simple, vegetarian cookbook, 1905
The battle for the truth. The contemporary nature of life court
The contemporary nature of healing, in a condensed form. Human salvation for body, mind and soul
The healing earth, nature and the old folk remedy and its wonderful healing of internal and external application. All true modern natural healing method on a Christian foundation
The Earth as a remedy. The old natural and folk remedies, and its wonderful healing of internal and external application. The true nature of healing, contemporary Christian basis
