It is, however, quite possible to cultivate some of the advantages of this temperament and to restrict the disadvantages. It is not necessary, for example, that anyone should be at the mercy of every transient impulse: this involves an enormous waste of energy, as would the voyage of a ship which should suffer itself to be blown hither and thither by every passing breeze. We only respond to that to which we are mentally attuned, and our minds pick up out of the welter of errant thought only those which correspond to the note we sing. This, then, suggests that by attuning the mind to certain things we automatically throw it out of tune with conflicting ideas. The successful artist, as a rule, is one who has learnt to render himself oblivious to distractions, and so is enabled to concentrate his attention solely on the work in hand. The artist who will be permanently unsuccessful is the one whose enthusiasms attract him first to one thing and then another, never allowing him to remain absorbed by the one thing long enough to bring it to a satisfactory issue. Auto-suggestion applied to this point of inculcating response to certain things, and immunity from the influence of others, is an easy and extremely practical help. One characteristic of genius is an extreme fertility in making mental associations. A central object comes into mind, and immediately the mind of the genius, by contrast, comparison, analogy, inference, and imagination, weaves around it a wealth of possibility: the dull-witted man sees the same, but his mind travels no farther than the actual vision. The quick mind supplies the apt repartee, while the dullard thinks of the appropriate reply next morning--if at all. The disadvantage of the latter mind is that it does not work easily, the danger of the former is that it may work too easily and get out of control. Where the central control does not suffice to keep a strong hand upon this easy-running mental machinery, it may quickly merge into eccentricity and possibly into madness. The insane show this same tendency to rapid, but irrelevant, association which lands them in incoherency: they make, or indulge in, associations which no normal person would allow. A genius is only a genius while the necessary selection and control over these associations is retained, when this is lost the genius passes into that insanity to which it is so closely associated. The same conditions and remarks apply to the artistic temperament, which itself is a mark of possible genius.