'The resolution of one physiological state into another becomes easier and more rapid after it has taken place a number of times.' (ibid., p. 291.)

Prof. Jennings illustrates this law by the behaviour of the stentor when subjected to injurious stimulation by carmine grains. The stentor is an infusorium found on decaying vegetable matter in ponds and resembling in its appearance a minute gramophone horn. The surface of the trumpet is covered with cilia, and those which fringe the trumpet mouth by their movement sweep water and its contents into the interior of the trumpet. When stimulated the stentor continues the motion of its cilia, but as the flow of carmine grains continues, it bends its stalk away from the stream. At a further spread of the current of carmine, it reverses the action of the cilia, sweeping away the water from its trumpet ; if the flood of carmine still continues, the stentor telescopes its trumpet. Should this stimulation by carmine be repeated after an interval when the stentor has again expanded its trumpet, the stentor will at once contract into its tube. This reaction illustrates the Law of Readier Resolution. If we call the state when the carmine grains begin to operate A, A passes into B as the stentor bends on one side. B passes into C as the stentor reverses its cilia, and C into D when the stentor contracts into its tube stalk. With repetition the series A-B-C-D becomes A-D wherein the physiological states corresponding to B and C are passed through so rapidly that they produce no reaction, but are resolved at once into D. A is representative of B and C in that the organism reacts to A as if B and C with their reactions had taken place.

'If the law of the resolution of physiological states is actually operative throughout behavior the effect would be to make behavior depend on the result of the animal's own action. This would produce behavior that is regulatory, such as we actually find to exist.' (ibid., p. 298.)

Memory then denotes the potentiality of a physiological state

for change in a given direction. How is this potentiality interpreted? The question is not easy to answer from Prof. Jennings's book. We may be back at 'Mneme' in a new guise under the phrase a physiological state'. With reference to this experiment and to another wherein the stentor was stimulated by a jet of water Prof. Jennings says,

'The behavior of the stentor under the conditions given is evidently a special form of the selection of certain conditions through varied activities. . . . The organism' tries' one method of action; if this fails, it tries another, till one succeeds. . . . Is the change in the behavior of stentor in accordance with its past history a phenomenon in any way similar in character to the learning of a higher organism? . . . The essential point seems to be that after the experience the organism reacts in a more effective way than before. . . . Stentor seems to vary its behavior only in accordance with the experience that either (1) the stimulus to which a strong reaction is at first given, does not really interfere with its activities, so that the reaction ceases; or (2) that the reaction already given is ineffective since the interference with its activities continues, so that another reaction is introduced.' (ibid., p. 178.)

To this passage Prof. Jennings appends this foot-note:

It is to be noted that nothing is said in this statement as to the Stentor perceiving these relations. The statement attempts merely a formulation of the observed facts in such a way as to bring out their relation to what we observe in higher organisms.' (ibid., p. 178.)

We read further:

'There seems to be no difference in kind. between associative memory and other sorts; they are based on the same fundamental law. The existence of associative memory has often been considered a criterion of the existence of consciousness, but it is clear that the process underlying it is as readily conceivable in terms of matter and energy as are other physiological processes. Even in inorganic colloids, as we have seen, the properties depend on the past history of the colloid, and the way in which it has reached the condition in which it is now found. If this is conceivable in terms of matter and

energy, it is difficult to see why the law of the readier resolution of physiological states is not equally so.' (ibid., p. 334.) While possibly our statement of this law may not be entirely adequate, there would seem to be nothing implied by it that is specifically vital, in the sense that it differs in essential principle from the methods of action seen in the inorganic world.' (ibid., p. 334.)

This seems to be mechanism pure and undefiled. Yet if we look more closely at Prof. Jennings's account of reaction to stimuli and the resolution of physiological states, we become doubtful whether he succeeds in keeping within the limits he here prescribes. He hesitates to attribute consciousness to the lower organisms, but holds that the facts of behaviour suggest it.

So far as objective evidence goes, there is no difference in kind, but a complete continuity between the behavior of the lower and of the higher organisms.... The writer is thoroughly convinced, after long study of the behavior of this organism, that if the Amoeba were a large animal, so as to come within the experience of human beings, its behavior would at once call forth the attribution to it of states of pleasure and pain, of hunger, desire, and the like, on precisely the same basis as we attribute these things to the dog.' (ibid., PP. 335, 356.)

In describing the behaviour of the flat worm Planaria Prof. Jennings writes,

'The different physiological conditions are determined largely by the history of the individual worm, so that in this sense its behavior may be said to depend on its experience.' (ibid., p. 253.)

What is implied by the word 'experience' here? (cf. the passage quoted from p. 178.)

Again, what is to be made of a 'successful movement', which is selected because it is successful in causing a cessation of the stimulation? It is said to relieve the organism from the stimulating condition. If the organism in question lacks

sentience, it'experiences' neither the presence nor the absence of the stimulation; it is only some appraising critic who can attribute success or relief to the movements. Yet it is this very success and failure which is necessary for the description of what happens in the regulation of movement. Prof. Jennings repudiates the reflex theory of animal behaviour just because it has no place for the selection and regulation of response. He regards it as inadequate for a faithful account of animal behaviour. Everywhere he finds trial movements. Can 'trial', 'success', and 'failure' be given a meaning without some attribution of sentient experience to the behaving organism? This is a crucial question.

Without' overproduced movements', selection would have no scope, and without selection, the resolution of physiological states would in no wise serve the purposes of biological memory: the present response would not be a record of past success or past failure. We seem to have here the elements of a dilemma. On the one hand, Prof. Jennings's observations make him reject tropisms and reflexes as an inadequate basis for constructing an historical account of behaviour. On the other hand, his desire to be objective' in his methods leads him to avoid any overt attribution of consciousness to the organisms studied. Yet when he proceeds to argue from the comparison of the lower and higher organisms that since they behave alike, and the higher are conscious, therefore it is probable that the lower are conscious also, is he entirely free from the charge of petitio principii? Does the objective method which seeks to be historical, succeed in avoiding the horns of mechanism on the one hand and pampsychism on the other? The question is important in view of the claims of those who have taken over this method from biology with the intent of thereby refashioning psychology. They reverse Prof. Jennings's argument, claiming: Since they behave alike and the behaviour of the lower organism can be described

without the attribution of consciousness, therefore the behaviour of the higher can be similarly so described.

This new school of psychology must be considered in the next chapter.

II

MEMORY AND BEHAVIOURISM

In order to use the objective method in psychology and the objective method only, it is necessary to make psychology the study of man's responses to his environment.

The category consciousness with the subdivisions, knowing, feeling, striving, must disappear and be replaced by the single group of phenomena, bodily responses. The observer can distinguish between stimuli on the one hand and responses on the other, and thus the knowing, feeling, striving of the old psychology will give way to a relation between the body and the environment, or between one part of the body and another.

To the objection that such a psychology is another name for physiology, the reply is made that the response in which psychology is interested is always the response of the organism treated as an individual whole, even though the response be the response of some one organ, such as the eye.

It would be possible to raise at this point the question, for whom and in what sense is the organism a whole? But let us assume the observer and his understanding of an organism as a whole, neglecting any comment to the effect that introspection lies at the root of such comprehension.

Human responses can be classified in several ways. There are the overt responses involving the larger musculature, easily recognizable by the observer, and the responses which are made within the body itself. The latter are only revealed