I think those are all things you need for life.
But what you do need for specifically a PhD? I argue that "knowing stuff" is what is necessary -- and that indeed it's essentially the purpose of the whole academic institutiom.
But what you do need for specifically a PhD? I argue that "knowing stuff" is what is necessary -- and that indeed it's essentially the purpose of the whole academic institutiom.
"Knowing stuff" is enough to get you to the point where you can formulate a good research question, but being a good researcher is a much broader skillset than just knowing things. And consequently, just knowing things won't get you a Ph.D., because getting one requires you to talk about your research. A lot. Like, all the time. And after all, the last step in getting the Ph.D. is called a "defense", not an "examination", because you are not there to tell anyone what you know -- you are there to defend what you know, and that's a different skillset than gaining knowledge or even disseminating knowledge.
I guess all that is to say, you could know everything in the world, but if you lack the skills to tell anyone else about that knowledge, you'll never get a Ph.D.