Therapeutic nihilism is a contention that curing people, or societies, of their ills by treatment is impossible.
In medicine, it was connected to the idea that many "cures" do more harm than good, and that one should instead encourage the body to heal itself. Michel de Montaigne espoused this view in his Essais. This position was later popular, among other places, in France in the 1820s and 1830s, but has mostly faded away in the modern era due to the development of provably effective medicines such as antibiotics, starting with the release of sulfonamide in 1936. A variant of the belief is still held by many people who practice homeopathy and other forms of alternative medicine.
In relation to society, it was the idea that nothing can be done to cure society of the problems facing it. It was never mainstream thought and did not grow beyond its origins in early 20th century Germany. It had no main proponent save for the novelist Joseph Conrad whose writings reflect the theory.
The phrase Theraputic Nihilism is also included in the modern version of the Hippocratic Oath, traditionally taken by Physicians upon graduation. The statement is 'I will apply for the benefit of the sick, all measures [that] are required, avoiding those twin traps of overtreatment and theraputic nihilism.'
The modern version of the Hippocratic Oath was written in 1964 by Loius Lasagna, Academic Dean of the School of Medicine at Tufts University, and used in many medical schools today.