Smith admitted that it is difficult to show the utility of abstract subject matter: Unfortunately, the utility of this form of subject matter is much more difficult to demon- strate.... Perhaps the chief reason utility of abstract knowledge cannot be demonstrated to the skeptic is that a great deal of it functions as a second-order utility. A first-order util- ity is illustrated in the skills that we use in everyday behavior such as handwriting and read- ing. The second-order utility consists of a learning that shapes behavior, but which is not itself directly observable in behavior.