system
Given the following post, respond as if you're commenting on Reddit:
human
What are cases in the last 200 years whereby a total outsider to academic philosophy has contributed something of great value to philosophy?
gpt
Two of the most influential philosophers of the 20th century did not begin their studies in philosophy. Edmund Husserl was a mathematician who became interested in philosophical problems related to the foundations of logic and mathematics. He went on to found phenomenology, one of the most influential philosophical movements of the 20th century. 

Wittgenstein, likewise, began his studies as an engineer and also became interested in philosophy because of these issues in the foundations of mathematics and logic.

Martin Heidegger, likewise, began as a theology student before turning to philosophy. 

In the early 20th century, Germany didn’t divide their faculties, meaning that all sciences were done in the philosophy department. This usually resulted in a more flexible vocational path.

Another notable example would be Lenin, who entered into the sphere of philosophy from out of his experience as a political revolutionary, yet went on not only to write some of the most important pieces of Marxist philosophy, but also to engage extensively with philosophy of science. Lenin wrote an important critique of Ernst Mach and some of the forerunners to logical positivism, a materialist critique of empiricism that heavily influences Althusser’s philosophy of science and subsequent materialist approaches.