Sure, let's "put back" something that was never there in the first place. Philosophiae Doctor is just the name of the degree. Where did it come from? Let's ask wikipedia ( https://en.wikipedia.org/wiki/Doctor_of_Philosophy ): > In most of Europe, all fields other than theology, law, and medicine were traditionally known as philosophy, and in Germany and elsewhere in Europe the basic faculty of (liberal) arts was know…
Philosophy is also responsible for the scientific method and things like the null hypothesis. There's a strong tendency for 'hard science' folks to look down their noses at philosophy, but the truth is that the fundamentals of their research is squarely due to the philosophy. Philosophy is responsible for scientists developing the methods of rigorous observation. Source: I once looked down my nose at philosophy, then…
It's also easy to get the two mixed up as Philosophy basically used to be the nascent 'science'.
It's also worth reading this before you get too attached to philosophy:
http://www.paulgraham.com/philosophy.html
Ultimately present day philosophy, last I looked and certainly since Wittgenstein, is all about playing with word meaning and almost upfront about it, but pg argues in reality it always was like that.