What 4 figures had th emost impact in 19th and 20th century thinking?

Question

socialogy, philosophy etc....

Answer 1

I would have to say the figures are square, tetrahedron, hourglass and hexagon.

Answer 2

There are 3 on which there is widespread consensus: Sigmund Freud, Charles Darwin and Einstein.

The forth is harder to picture because there are several scientists that have been very important but have not had as much impact on XX th century thinking as the former ones. Chomsky, Dawkins and Umberto Eco are the most cited but someone like Gandhi sure changed things by his teachings on a humanistic level of thought.