THE word imagination, like most of the terms used to express vital and organic functions, is vague and ambiguous. Of those who have, whether of set purpose or incidentally, dealt with imagination as a quality or essence in poetry, the greater number have either not defined the term at all, or have given some definition of it which has not satisfied any one except themselves. Both courses are open to exception. But the former of them, the absence of any definition, is the source of much confusion; for there are fallacies which the existence of some definition, even if it were only approximate and provisional, would at once render obvious, but which in the absence of anything of the sort may elude observation and must in any case perplex argument. The defence made for avoiding definition would probably be the same as is made for refusing to define poetry; namely, that in a general way, the import of the term is a matter of common knowledge, and that any attempt to define it more closely only leads to wrangling over abstractions without adding anything to real knowledge, or even to real clearness of thought.
It is true that a strict definition of any vital process, just as of life itself, is theoretically unattainable. Life cannot be subsumed under any larger concept, nor can it be expressed in terms of anything which is not itself alive. Poetry, as a function of life, is subject to