Philosophy isn't anywhere on the Mohs scale of sciences—it's not a science at all. Each philosopher has their own idea about what philosophy is, but I'm not aware of any who think it's a science. That's one way to tell the difference—a philosopher asking "what is philosophy?" is doing philosophy. A physicist asking "what is physics?" is doing philosophy, philosophy of science. Actually it's mostly philosophers who ask that.
Science was originally[0] a part of philosophy—natural philosophy—but that's a different story. Part of Socrates' originality was that every previous philosopher concerned themselves with physics and other physical sciences, but he was just concerned with the human world.
https://en.wikipedia.org/wiki/Mohs_scale
[0] And until quite recently! The word scientist was only coined in 1834. And "The predominant modern use [of the term "science"], "natural and physical science," generally restricted to study of the phenomena of the material universe and its laws, is by mid-19c."