Amongst philosophers, Socrates is an example of a genius with a great influence on human history who never wrote anything. Almost all facts which are known about his revolutionary ideas are written by his students like Plato and Xenophon.
Question: What are examples of genius mathematicians in modern or ancient eras whose ideas had a great influence on development of mathematics but never wrote or published anything?
Best Answer
There are influential posthumous papers by authors who did not publish them.
Galois had an immense influence on algebra because of the publication of something he wrote the night before he died in a duel. He gave us the word "group".
Thomas Bayes had an influential posthumous paper in which he found the conditional probability distribution of a random variable $P$ whose marginal distribution is uniform on $[0,1]$, given the observation of the number of successes in $n$ trials that are conditionally independent given $P$, where the conditional probability of success on each trial, given $P$, is $P$. He did publish things while he lived.
Mary Cartwright never published her proof of the irrationality of $\pi$. A question she set on an examination was to fill in its details. We know of it only because Sir Harold Jeffries included it in an appendix in one edition (and not in other editions) of one of his books, and he leaves the impression that he knew of it only because of its occurrence on that examination.