The name “Brother Sebastian” was taken by a Maryknoll Brother, who draws cartoons. I suppose this is a case of life imitating, uh, well, um, something. However, these Brother Sebastian cartoons are drawn by Chon Day, (Chauncey Addison Day) a very well known cartoonist from the 1940’s onward. Brother Sebastian was a staple in Look magazine. Look is no more, but Brother Sebastian lives on in cartoon collections. Chon Day’s minimalist style is easily recognized in other magazines from that time.
These cartoons, from The Saturday Evening Post, are quite minimalist in their presentation. They have a few more Chon Day cartoons, here.
The above New Yorker cartoon is not minimalist, must have been in his later years.
He gives us a nice bio, but nowhere does he say just how he started on this strip.
Brother Sebastian even has a short video, called Fancy Footwork.
Here is a good collection of his cartoons, courtesy of a gentleman named Mike Lynch.