Comment by jldugger

Here is Fisher, in a letter to the editors of _Nature_ (perhaps the most prestigious journal imaginable) "Cancer and Smoking"[1]:

> If, for example, it were possible to infer that smoking cigarettes is a cause of this disease, it would equally be possible to infer on exactly similar grounds that inhaling cigarette smoke was a practice of considerable prophylactic value in preventing the disease, for the practice of inhaling is rarer among patients with cancer of the lung than with others. [...] There is nothing to stop those who greatly desire it from believing that lung cancer is caused by smoking cigarettes. They should also believe that inhaling cigarette smoke is a protection. To believe either is, however, to run the risk of failing to recognize, and therefore failing to prevent, other and more genuine causes.

As a geneticist, he of course took the position that it was a smoking gene confounding the causation.

[1]: https://www.nature.com/articles/182596a0