I think stonebench deals with 思維 as if a mathematician

deals with math. He isn't doing 思維 but studying it as an object. The mathematcian manipulates symbolic systems in order to reach the mathematical reality suggested by the symbolic systems invented by men.

Imagine, God being a mathematician, he wouldn't need any symbolic sysyems, he simply sees math in its entirety. Since stonebench isn't God, therefore he does math with symbolic systems.

Just guessing...