Last week, I read Wikipedia's article on Alexander Grothendieck. It lists his twelve greatest contributions to mathematics as accounted for in Grothendieck's own *Récoltes et Semailles*. The final item on this list is

> The "schematic" or "arithmetic" point of view for regular polyhedra and regular configurations of all kinds.

A quick search revealed an unanswered [MathStackExchange][1] post with the same question, from 12 years ago!

Can anyone elaborate on this statement, or recommend a treatment of this topic?




  [1]: https://math.stackexchange.com/q/133399/1089874