How many brain regions do you want to study?

Neuroanatomists categorize themselves into "clumpers" and "splitters' based on how they like to organize the brain. Clumpers prefer to simplify the brain into as few sections as possible, while splitters divide the brain into thousands of pieces, all with their own Latin or Greek names. . . .

. . .

Most of us, however, fall somewhere in between these camps and organize the brain into a few hundred parts. I am a splitter and I like having thousands of specific parts to study. But for the sake of simplicity, especially when teaching or writing a paper, I like to organize the brain into a 3x3x3 "Rubik's Cube" pattern. This twenty-seven-part brain is as simple as I'm willing to go and still be able to sleep at night without violating Einstein's first law of simplicity in science: "Everything should be made as simple as possible, but not simpler."

James Fallon, The Psychopath Inside: A Neuroscientist's Personal Journey into the Dark Side of the Brain (New York: Current, 2013), pp. 47-48.

Einstein's rule about simplicity might be a bit too simple. Quote Investigator has a long discussion, tracing it to a paraphrase ("He said, in effect, that everything should be as simple as it can be, but not simpler.") that was later taken as a quotation. Einstein actually said (in 1933):

It can scarcely be denied that the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience.

Quote Investigator (citing Alice Calaprice, ed., The Ultimate Quotable Einstein).