_Such devices have a special and temporary utility_; we have all taken examinations, and probably we have all had recourse to them on a larger or smaller scale. Many of us have paid the not infrequent penalty; we have remembered our mnemonic doggerel, but have forgotten the key to it, and so have forgotten the events or numbers that it was meant to recall; there is always that danger. _No scheme of memory-aids that is universally applicable and universally reliable has been or can be discovered_; there is no royal road to learning. In so far as a mnemonic rule follows the laws of associative tendency, as for many minds the local or topographical rule seems to do; or in so far as it chimes with some peculiarity of individual thinking; in so far, it will be of practical service in daily life; that is the most that can be said. § 44. =The Idea of Imagination.=—We think of memory as reproducing the old, and of imagination, no less positively, as producing the new; the very word _poet_ means the maker, and the word _artist_ means the fitter or joiner. Imagination cannot, of course, give us new qualities of experience; we cannot imagine a new colour, different from all known colours, or a new sensation—say, a specific sensation of electricity—different from the known sensations of skin and underlying tissues. _Imagination does, however, give us novel connections_; and experiment shows that an idea comes to us as imagined only if it comes as unfamiliar, with the feeling of novelty or strangeness upon it. In real life, the =feeling of strangeness= is soon swamped by alien feelings, by the artist’s joy or pride, dissatisfaction or despair; in the laboratory, it appears strongly by itself. The observers speak of a feeling of novelty, of personal detachment, of creepiness, of weirdness, of something out of the ordinary, of peculiar discomfort. Compare this list of terms with a sentence from Lafcadio Hearn’s last book: “The outward strangeness of things in Japan produces a queer thrill impossible to describe,—a feeling of weirdness which comes to us only with the perception of the totally unfamiliar”; there is no doubt that the same experience is intended. It is, at first thought, a little surprising that an idea of imagination, which after all derives from the observers’ own experience, and which is obtained under the rather tame and colourless conditions of a psychological experiment, should have so strong a tinge of feeling. Yet we need not be surprised; for we have already learned that the novel stimulus has power to compel the attention; it stands alone and unrelated; and for that reason it startles and arrests us (p. 94). If the ideas aroused in the laboratory mattered, if they were practically important for their owners’ careers, then the feeling of strangeness would, as we have said, be overborne by other feelings; but they do not matter, and so can be developed and observed for what they are.