Estelle M. Phillips and D.S. Pugh, How to Get a Ph.D,1987
The holder of a doctorate is someone who is recognized as an authority by the appropriate faculty. In modern terms it is useful to think of this as becoming a full professional in your field. Let us try to spell out what becoming a full professional means:
First, at the most basic level it means that you have something to say that your peers want to listen to.
Secondly, in order to do this you must have a command of what is happening in your subject so that you can evaluate the worth of what others are doing.
Thirdly, you must have the astuteness to discover where you can make a useful contribution.
Fourthly, you must have mastery of appropriate techniques that are currently being used and also be aware of their limitations.
Fifthly, you must be able to communicate your results effectively in the professional arena.
Sixthly, all this must be carried out in an international context; your professional peer group is worldwide. You must be aware of what is being discovered, argued about, written and published by your academic community across the world.
So, if you are a currently Ph.D candidate, you’d better review what you did and what you are doing now always and ask
“Am I adequate now?”
I am not.