have in mind some description of Julius Cæsar: "the man who was assassinated on the Ides of March," "the founder of the Roman Empire," or, perhaps, merely "the man whose name was Julius Cæsar." (In this last description, Julius Cæsar is a noise or shape with which we are acquainted.) Thusour statement does not mean quite what it seems to mean, but means something involving, instead of Julius Caesar, some description of him which is composed wholly of particulars and universals with which we are acquainted.
The chief importance of knowledge by description is that it enables us to pass beyond the limits of our private experience. In spite of the fact that we can only know truths which are wholly composed of terms which we have experienced in acquaintance, we can yet have knowledge by description of things which we have never experienced. In view of the very narrow range of our immediate experience, this result is vital, and until it is understood, much of our knowledge must remain mysterious and therefore doubtful.
