If You're So Smart, How Come You're Dead?
As Steven Shapin explains in "Descartes the Doctor: Rationalism and Its Therapies," seventeenth century philosophers were painfully aware that that "the ability to prevent and cure disease, to alleviate suffering and extend human life has recurrently been used as a public test of the truth and power of philosophic and scientific systems . . ."
Thus, although Rene Descartes is best known today as "the father of modern philosophy," he was also in the habit of doling out hands-on medical advice and making claims about his future longevity.
You can find a full list of Prof. Shapin's works in DASH here.