The special communicative gifts, either active or passive, which have been alluded to, are no peculiar irreducible abilities. They can be described in terms of activities already mentioned. The use of past similarities in experience and the control of these elements through the dependence of their effects upon one another, make up the speaker’s, the active communicator’s gift. Discrimination, suggestibility, free and clear resuscitation of elements of past experience disentangled from one another, and control of irrelevant personal details and accidents, make up the recipient’s gift. We may now consider these more closely.

Certain favourable and unfavourable special circumstances in the temperaments or characters of the persons concerned may be set aside. Thus courage or audacity, enterprise, goodwill, absence of undue pride or conceit, honesty, humaneness, humility in its finest sense, humour, tolerance, good health, and the Confucian characteristics of the ‘superior man’ are favourable general conditions for communication. But we will assume them present in sufficient degree and pass on to the less evident because more fundamental conditions. In the first place all those which we have enumerated as desirable in the recipient are also necessary in the artist. He is pre-eminently accessible to external influences and discriminating with regard to them. He is distinguished further by the freedom in which all these impressions are held in suspension, and by the ease with which they form new relations between themselves. The greatest difference between the artist or poet and the ordinary person is found, as has often been pointed out, in the range, delicacy, and freedom of the connections he is able to make between different elements of his experience. “All the images of nature were still present to him,” says Dryden, with felicity, of Shakespeare, “and he drew them not laboriously but luckily.” It is this available possession of the past which is the first characteristic of the adept in communication, of the poet or the artist.

Availability, not mere possession, however, is what is essential. Many people are endowed with memories of marble upon which time can do little to efface even the slightest mark, but they benefit little from their endowment. A merely repetitive retention is rather a disability than an asset in communication, since it makes the separation of the private and irrelevant from the essential so difficult. Persons to whom the past comes back as a whole are likely to be found in an asylum.

What is in question here is not memory, in the stricter sense in which past experience is dated and placed, but free reproduction. To be able to revive an experience is not to remember when and where and how it occurred, but merely to have that peculiar state of mind available. Why some experiences are available and others not is unfortunately still a matter for conjecture merely. The difficulty upon most accounts, Semon’s for example, is to explain why all our past experience is not being revived all the time. But some plausible conjectures are not difficult to make, and the absence of clear evidence or conclusive proof should not prevent our making them if they are recognised for conjectures.

How far an experience is revivable would seem to depend in the first place upon the interests, the impulses, active in the experience. Unless similar interests recur its revival would seem to be difficult. The original experience is built upon a number of impulses; it came about only through these impulses. We may even say that it is those impulses. The first condition for its revival is the occurrence of impulses similar to some of these.

The patient in the asylum occupied in reliving the same piece of experience indefinitely does so (if he does) because he is limited very strictly in the range of his possible impulses, other impulses not being allowed to intervene. Hence the completeness with which he is said to reconstruct the past. Most revival is distorted because only some of the original impulses are repeated, new impulses being-involved and a compromise resulting.

The impulses implicated in experiences may be many and varied or few and alike. An experience which has a very simple impulse structure will, we may suppose, tend to come back only when these impulses are again relatively dominant. Other things being equal it will have less chance of revival than an experience with a more complex structure. Recalling the illustration used in Chapter XIV, the broader the facet the more numerous are the positions from which the polyhedron will settle down on that facet. It is a first principle of psychology that the partial return only of a situation may reinstate the whole, and since most impulses have belonged in the past to many varied wholes there must evidently be much rivalry as to which wholes do actually recur. What seems to decide the dispute more than anything else is the character of the original connections between the parts. As has recently been emphasised by the exponents of Gestalt-psychologie, mere original contiguity or simultaneity is comparatively powerless to control revival. Compare the learning of a geometric theorem by heart with understanding it, or even a brief study of some building with mere daily familiarity.

What then is the difference between understanding a situation and the more usual reactions to it? It is a difference in the degree of organisation of the impulses which it arouses. It is the difference between a systematised complex response, or ordered sequence of responses, and a welter of responses. We must not take ‘understanding’ in too specialised a sense here, or we shall overlook the immense importance of this difference in determining revival. We are accustomed to make an artificial distinction between intellectual or theoretical and non-intellectual or emotional mental activities. To understand a situation in the sense here intended is not necessarily to reflect upon it, to inquire into its principles and consciously distinguish its characters, but to respond to it as a whole, in a coherent way which allows its parts their due share and their proper independence in the response. Experience which has this organised character, it is reasonable to suppose, has more chance of revival, is more available as a whole and in parts, than more confused experience.

Contrast the behaviour of the sleepy and the fully awake, of the normal man with the lightly and the more deeply anæsthetised patient, of the starved or fevered with the healthy. To describe these differences in neural potency, and to mark the degree of physiological efficiency, Dr Head has recently[†] suggested the term vigilance, a useful addition to our symbolic machinery. In a high state of vigilance the nervous system reacts to stimuli with highly adapted, discriminating, and ordered responses; in a lowered state of vigilance the responses are less discriminating, less delicately adapted. Whether we are considering the decerebrate preparation or the intact poet, the simplest automatisms or the most highly conscious acts, what happens in a given stimulus situation varies with the vigilance of the appropriate portion of the nervous system. The point as regards revival can be put conveniently by saying that experiences of high vigilance are the most likely to be available. The degree of vigilance of the individual at the moment at which revival is attempted is, of course, equally but more evidently an important factor.

The answer then, at least in part, to the problem of how the poet’s experience is more than usually available to him is that it is, as he undergoes it, more than usually organised through his more than usual vigilance. Connections become established for him which in the ordinary mind, much more rigid and exclusive in its play of impulses, are never effected, and it is through these original connections that so much more of his past comes to be freely revivable for him at need.