1931

Every major Western philosopher since 1500 has also been a math crank on the side- Hobbes, Hegel, Marx, etc. https://t.co/UssiTdgoZe

— Quantian (@quantian1) February 7, 2021

The year that "string" came to an end.  Kurt Godel published his Theorem of Incompleteness, and shattered the suppositions of Principia Mathematica by Russell and Whitehead.  Russell became a peace activist, Whitehead wrote an entirely un-mathematical work of philosophy which lived only as the basis for a late 20th century and obscure (and tiny) school of theology.  They remained math cranks; but the connection between math and Western philosophy was never the same.

I can also think of several major philosophers between 1500 and 1931 that didn't bother all that much with math.  But, as I say, Russell and Whitehead drove that ship directly onto the rocks, and that rock was Kurt Godel's massive achievement in logic.  That ship has not sailed since.

Oh, it's worth noting that, when he became a U.S. citizen, Godel has studied the U.S. Constitution and found an inconsistency in it which could allow the U.S. to become a dictatorship.

The more you know.....