Now it appears to me that recent researches all point to the fact that the mental processes of animals are mainly—I do not say entirely, though I myself still incline to that opinion—but at all events mainly, on the perceptual plane. They tend to show that animals, even the monkeys, deal with situations as complex unity-wholes. The method of learning is chiefly dependent on practical behaviour which, carried out with varied and persistent—often restless— activity, leads the animal unsystematically to stumble on new associations between such behaviour and the situation within which it arises. But it also appears to me that a very large proportion of human process is predominantly upon the perceptual plane. I say "predominantly" because even this section of human activity is inevitably influenced by the ideational section which is superinduced thereon. And there is, I repeat, no little difficulty in determining its range, as perceptual, just because our psychological language almost necessarily leads us to describe it on the basis of perceptual experience systems of knowledge can be built. This is the product of ideational process. It involves an ideal or schematic construction. And when situations are viewed from the standpoint of a system of knowledge their salient features have not only " meaning" for practical behaviour, but also " significance" in relation to that system. They are apperceived as particular examples which illustrate some general scheme or principle. And it is here that psychology comes into touch with normative science. No doubt normative science, as its name implies, deals with standards of reference—in ethics, for example, with standards of " ought." But this is only an implication of the fact that the particular act is viewed in its relation to an ethical scheme of conduct. Impulses arise within the situations as they occur and as they are dealt with in and for themselves. But motives, as the term is used in ethics, imply the relations between these several situations and a system of ideals. Only on the ideational plane do there emerge considerations looming up beyond the situations into a prudential, moral, or other scheme; behaviour is thus raised to the level of conduct; and a situation is developed, not only in accordance with the impulse-value arising therein, but in accordance also, and in greater degree, with the motive-worth for a system.

In this brief sketch I can scarcely hope to render clear and convincing the distinction between perceptual process on the plane of intelligent behaviour and conceptual process on the plane of rational conduct. And, no doubt, to some the difference between "meaning for practical experience" and "significance for systematic knowledge" may not be obvious—or may appear too slight to bear the stress I have laid upon it. None the less, I regard it of cardinal importance as affording one of the criteria of wholly different stages of mental development. How can I help the reader to get the necessary point of view? Perhaps an illustration from such games of skill as tennis, or cricket, or golf may serve. For most of those who simply play with more or less success but without troubling their heads about the theory or the science of the game, their skill is so far on the perceptual plane. The way in which the tennis ball comes off the opponent's racket and skims over the net; the manner in which the cricket ball leaves the bowler's hand and pitches; how the golf ball lies, the look of the course for an approach shot, the slope of the green for one's putt—all these are full of meaning for the practised player. As the result of previous experience, each immediately suggests the requisite response in play. There is a direct association between such a situation in the game and the appropriate action. So, too, every movement of the button on his adversary's foil means for the fencer such and such a guard. There. is no time to think out the right parry. Skill depends on a body of experience begotten of constant practice, and a man may be a first-rate exponent without having any systematic knowledge in terms of which he can explain how and why and on what principles he acts in this or that particular way. It is simply the net result of having so acted in hundreds of similar situations. And the most skilful player is the one whose action is the natural and spontaneous outcome of the circumstances of the moment. The successful driver at golf walks up to the tee, takes his line, and smacks the ball a couple of hundred yards. If one has to think anxiously about the proper stance, the latest hints as to how to correct a faulty swing, the paramount necessity of keeping the eye on the ball and away from the hazard in front, and so on, the chances are against him; that way foozling lies. Of course I am not urging that the good player must be ignorant of first principles in the art and science of golf. In his rational moments he has probably paid some attention to them; but he need not know much about them to be a good golfer, and the less he thinks of them when he is making his stroke the more liable is he to feel that he is on his game, that it is his day, and that somehow he cannot go wrong.

Now let us suppose that he wants to know, for his own satisfaction or to explain to others, how the game should be played. Improvement in the art, or exposition of its rationale, is a motive beyond the enjoyment of the passing hour. What must he do? He has to analyse the strokes into the component movements which he has hitherto felt or seen as unity-wholes. He compares the stance and swing of professionals and scratch men. Amid many idiosyncrasies he finds certain essentials in each case that he can accept as a model. These he selects from the non-essentials. By abstraction and generalisation he reaches general principles. He frames an ideal of effectiveness and style; he proceeds to the application of these general principles to his own particular case, and probably finds it no easy matter; or, as a critic, to the play of others, a less difficult task. Just in so far as he is able to do so, he realises the significance of his faults—the relation of his own poor stroke to the ideal, the way the ball ought to be played, why he has sliced or pulled or skied. He has added to his practical experience a system of knowledge. This he could never have reached without analysis, comparison, generalisation, and the application of abstract principles to the concrete case. This involves not merely perceptual but ideational and conceptual process. And of this kind of mental procedure animals, with all the wonderful skill they exhibit in so many ways, show little or no evidence.