alt Hacker NewsAn MD does not practice science.
Science is a process of discovering new knowledge through experiments.
An MD is much more akin to an engineer that applies scientific knowledge (and yes, some proportion of both MDs and engineers do create new knowledge through experiments and thus do science, but it's not the baseline expectation).
"Practicing" something means applying it. It's similar to how practicing law and creating law are related but not the same thing.