In the second half of the 18th century, a new understanding emerged of the concept of consciousness and its opposite, the unconscious, and of mental illness. An interest arose in the correct treatment of mentally ill people, as well as new ideas for practical and healthy architectonic frameworks in these people's lives. In the years around 1800, various Danish architects submitted designs for a mental hospital in Copenhagen. The four proposals, from 1792, 1798, 1802 and 1805, have been interpreted as a clear illustration of a chronological development in hospital design for mentally ill people. However, this was not a case of evolution. The four architects -- Andreas Kirkerup, C.F. Harsdorff, Philip Lange and Jens Bang -- were given different conditions, and their individual ideas and approaches varied. The four projects should rather be seen as personal architectonic expressions, which succeeded to varying degrees, reflecting a line of thought that academic literature today would describe as environmental determinism, in other words how individuals are shaped by their physical environment. Kirkerup's project from 1792 was constrained by the demand to reuse existing buildings, yet it featured several pioneering solutions to practical problems, which the next two proposals dealt with less successfully. Harsdorff's complex consisted of three buildings, one of which with two adjacent wings with cells was reserved for mental health patients, although the project revealed a poor architectural grasp of mental health care. Lange's mental hospital from 1803, inspired by foreign designs, comprised a circular central building with three radiating wings, yet Lange was more interested in geometry than function. The 1805 proposal was the most advanced, not because it was the most recent, but because it was designed by Bang, who was both a trained architect, at the Royal Danish Academy of Fine Arts, and a qualified doctor. He practised medicine for thirty years, becoming the deputy mayor of healthcare in Copenhagen. Bang had the prerequisites to create functional, people-friendly architecture that lived up to the latest international principles. His design consisted of a fourbuilding complex, complemented on three sides by semi-circular wings. The fourth side featured a low portal and corner pavilions. The proposed hospital allowed patients to socialise yet enjoy a private life too, with fresh air, green surroundings, baths and other hygiene facilities. For various reasons his proposal for Sankt Hans Hospital was never built. Yet it was the first planned hospital in Denmark -- and even in Europe one of the first -- to embody modern concepts acknowledging the influence of architecture on mental health. These ideas today, in another theoretical framework, form the foundation in the field of healing architecture. [ABSTRACT FROM AUTHOR]