and MD is an apprenticeship in the craft of clinical medicine. With it you will learn to treat patients. You will not necessarily learn to run and design experiments. Most of the figuring out of problems as an MD is done via learning tons of facts and then applying algorithms as if second nature.
A PhD is designed more to teach you to actually think, to actually solve problems. You do this within the framework of the scientific method (observation -> hypothesis -> test, etc) but there are less often pre-defined algorithms that you just follow. A PhD alone will not teach you necessarily to interact with patients and you will not be licensed to prescribe drugs.
Note I say "necessarily" in each case as obviously there are some MDs who end up doing research and some PhDs who do clinical research or treat patients (eg clinical psychologists).