What they've said about Harris's cartoons:

The humor in science that is most widely laughed at comes from non-scientists, like the cartoonist Sidney Harris. - Robert B. Swain, The New York Times Book Review

Harris is programmed with a powerful algorithm for finding incongruous associations. - Dennis Flanagan, American Scientist Magazine

Harris is different. Harris plays with science and technology... and he's funny. - Algis Budrys, Magazine of Fantasy and Science Fiction

Sidney Harris offers us a gift of humor and environmental sensibility in a cartoon wrapper. - Whit Gibbons, National Public Radio

By my criterion of humor, whatever it may be, Harris is successful about 99% of the time. - Nobel Prize Laureate Linus Pauling