No doubt the word 'intelligence' properly signifies rather an aptitude for acquiring knowledge than knowledge already acquired; but I do not think this aptitude is acquired except by exercise, any more than the aptitude of a pianist or an acrobat. It is, of course, possible to impart information in ways that do not train intelligence; it is not only possible, but easy, and frequently done. But I do not believe that it is possible to train intelligence without imparting information, or at any rate causing knowledge to be acquired.
Source: On Education, especially in early childhood, 1926, chap. 2 The Aims of Education