The real study of an art student is generally missed in the pursuit of a copying technique.
I knew men who were students at the Academie Julian in Paris, where I studied in 1888, thirteen years ago. I visited the Academie this year (1901) and found some of the same students still there, repeating the same exercises, and doing work nearly as good as they did thirteen years ago.
At almost any time in these thirteen years they have had technical ability enough to produce masterpieces. Many of them are more facile in their trade of copying the model, and they make fewer mistakes and imperfection of literal drawing and proportion than do some of the greatest masters of art.
He then explains what the “real study” of an art student is, but it's not real helpful to us. Obviously, the kind of people he's talking about never had anything of their own to say— they never approached it with the attitude that they were already an artist, and that they were just acquiring craft to help express it. That last paragraph is extremely important, as the current generation of players may be the most over-practiced in the history of American music, at least.
I think possibly, musicians are a little more reliant on knowledge acquired through study than are painters. If learning to paint is like learning a second language— everyone is comfortable with the visual world, and can easily form ideas about what he would want to paint— learning to play the drums is more like learning a first language; without it, you can't even conceive of what a musical idea is. It's as if you took up painting, but first somebody had to tell you what a dog is, or a tree, a house, or an apple, and how to tell them apart from each other. It's why little kids can make pictures with recognizable things in them, but when they pick up an instrument it's pure noise.
This passage is also interesting:
It is useless to study technique in advance of having a motive. Instead of establishing a vast stock of technical tricks, it would be far wiser to develop creative power by constant search for means particular to a motive already in mind, by studying and developing just that technique which you feel the immediate need of, and which alone will serve you for the idea for the emotion which has moved you to expression.
It's a little different for us as drummers, but you can see how it relates. Certainly online the conversation is dominated by talk of particular techniques or technical ideas. The attitude Henri is talking about would look more like having a lot of love for music, and learning a baseline functional technique, how to improvise, and how to play actual music, and letting that inform any additional special technical things you want to acquire.