indefinite the subjective accompaniment. Practice alone is the improving factor. In more complex processes like writing the learner is able to assume an objective attitude and direct and criticise his own activities and to shorten, by choosing new methods or avoiding observable mistakes, a process which would otherwise require much mechanical repetition. In still higher operations, like arithmetical calculations, consciousness of the process is still clearer. It acts vicariously for practice, which takes a subordinate rôle. The rôle of consciousness is similar to that of the teacher who can do little for one learning feats of muscular skill save give a few simple instructions, leaving the rest for the pupil to get by the hit and miss of practice; but in more complex activities he can act as a pattern, giving methods and pointing out deviations from them. Since right methods and easier work result in a widening of consciousness, this will leave the pupil's attention free for still further advances.

SUMMARY

In Part I we have considered consciousness as an ultimate fact, undefinable, identical with awareness. Unconsciousness denotes for us its opposite- entire absence of awareness, that which is entirely outside of our experience at any moment of time. Subconsciousness, for which we prefer to substitute "perceptual" factors, gives focal consciousness its qualitative character. Subconsciousness is consciousness of a less distinct degree. Divided consciousness, such as is present in cases of multiple personality, is best called "co-consciousness."

The question of the existence of "unconscious psychic processes," i. e., psychic accompaniments of physiological processes lacking awareness, depends for its answer on one's metaphysical concepts, which are in the end a purely temperamental matter. Denying them leads to the interactionist position. Throughgoing psychophysical parallelism demands the assumption of psychic factors accompanying physiological changes, and this position we have taken, insisting, however, that such "psychic'' processes are qualitatively different from anything which enters into consciousness. According to such a view one may speak of physiological processes in addition to "unconscious psychic processes.''

We have incidentally reviewed the arguments pro and con as to the presence of "unconscious' factors and their influence on mental phenomena. Our main interest was, however, in the relation of consciousness to learning. From general observation we have seen no case of learning where one is absolutely unconscious, yet one may be unconscious of the

end, the process and even of the development of the habit or association itself.

Our own experimental results are the following:

Our experiments on the nonsense-syllable material give chiefly negative results, but justify, so far as the conditions of the experiment permit, an inference that what is entirely outside of consciousness, though it is in such a position that it might easily become conscious, has no great effect, positive or negative, on the learning of the same material when it is presented later to clear attentive consciousness.

2. In the experiments on the "Motor Set" (Motorische Einstellung) we find that a habit may be formed despite the fact that one is unconscious that one is forming it. Yet, withal, attention to the task produces in all cases a more definite habit, a stronger "Einstellung," than that which is caused when one is almost unconscious of his performance. Attentive consciousness without doubt is accompanied by greater tension in the particular muscles involved in the current activity of the organism and in their nervous connections. Here activity is concentrated. The more fully the physiological mechanism is thus put into activity the more it is affected in the direction of easier and more efficient activity of the same sort.

3. The experiments on throwing at a target involved learning of a sensory-motor kind, the doing of a definite thing: it was practice with a fixed aim in view. Here focal consciousness was almost entirely projected on the target, the ball and hand occupying a peripheral place. Conscious control was exercised only over the grosser parts of the process. Methods gradually changed, and improvement appeared, without conscious change or control. The sensations from the arm and body no doubt contributed to the improvement, but these were always at the "perceptual" level and consisted rather of an undifferentiated background.

4. In the writing experiments conscious direction of the process and methods was more marked. At first consciousness is bound down to the general execution of the task. The more general, larger elements, becoming automatic, leave consciousness free to turn to details, when disadvantageous methods are noticed one by one and eliminated. Unconsciously modifications in the method crop out, and as consciousness becomes freed from details these are noticed, practiced, and improved upon. This sometimes results in a considerable change of adjustment of the different factors. 5. In the experiments on mental multiplication consciousness had a more immediate effect than in the more "muscular sorts of learning. Here advantageous methods occurred to the

subjects while they were working, or between the experiments, and when these were adopted the improvement was immediate and permanent, whereas in the more "muscular" sorts of learning one's muscular co-ordinations had to be practiced somewhat before the new method was perfected. In the number experiments, just because one is alive to the situation, he notices clumsy methods and slight errors, and is therefore ready to improve upon them. After a method was consciously developed, however, it was soon used unreflectingly-it became a habit. In proportion as an activity is conscious, consciousness is an aid or even an essential factor in its acquisition. This applies to details and part-processes as well as to the larger units of activities.

CONCLUSIONS

In conclusion we may say that in learning of any sort both conscious and unconscious factors exist. Unconscious factors are those involved in the fixing of the association by practice, and the cropping out of modifications of behavior subsequently utilized by consciousness.

The more intellectual and highly conscious the material to be learned, the more direct and immediate the effect of conscious control. Practice results in a standing out of common features of the process; these are focalized, and generalized into rules for new and better procedure, which immediately takes place.

In complex processes involving both an intellectual and a muscular side, the activity as a whole is conscious. Details are gradually mechanized, leaving attention free to attack new difficulties. Factors of the activity which are at first only at the "perceptual" level become clearly conscious, are then practiced and improved upon, and finally become mechanized and unconscious again. Consciousness is a corrective agent, eliminating errors, improving on elements unconsciously developed, and organizing the whole procedure. In learning simple muscular co-ordinations consciousness is focussed entirely on the end-on the outcome of the movement. One is only dimly aware of the different sensations and feelings entering into his bodily adjustment, and should any of these become the object of attention, disturbance of co-ordination results.

Learning can progress, however, without consciousness of the end or of the fact that one is learning, but even here a high degree of attention to one's task brings more marked results than work under distraction.

So far as our experiments go, factors never entering consciousness have neither a beneficial nor hindering effect on the learning.1

'The writer wishes to express her obligation for the faithful service of those who served as observers in the above experiments, and particularly to Dr. E. C. Sanford, in whose laboratory the work was done and at whose suggestion the subject was begun.

APPENDIX

Experiments with Meaningless Syllables

The general plan of these experiments has already been described in the body of the paper (pp 179 ff). It is only necessary here to record the details of procedure. The work was done with twelve-syllable series of meaningless syllables prepared in accordance with the method of Müller and Schumann's "verschärft normal" series,' except that additional letters were used to increase the possible number of syllables and to adapt them to English speaking observers familiar with German. There were 20 initial consonants and double consonants, (b, d, f, g, h, j, k, l, m, n, p, r, s, t, v, w, z, th, sh, ch), 19 finals, (b, d, f, g, j, k, l, m, v, p, r, s, t, v, x, z, th, sh, ch) and 14 vowels and diphthongs (a, e, i, o, u, y, ä, ö, ü, ai, oi, ee, oo, ou).2 These syllables were presented by means of a rotating drum of the intermittent-movement type, manufactured by Spindler and Hoyer of Göttingen, which permitted the syllables to remain at rest during the greater part of the time of their exposure. (See Fig. II which shows the apparatus from the back and side.) The syllables were seen through the opening of a suitable screen (See Fig. III) in such fashion that a single syllable of the series to be learned appeared each time between two syllables of series with which at the moment the observer had nothing to do. Thus the syllables

tam pog bex

would be shown, the observer being required to learn the middle series to which pog belongs, but having nothing to do at the time with the series to which tam and bex belong.

The observer sat before the screen and read the syllables of the middle series as they appeared through the slit. The experimenter sat at the side of the machine to the observer's right, his movements being entirely concealed from the latter by a large screen of gray cardboard. Directly in front of the apparatus and resting on the same table was a second drum, a portion of the surface of which could be seen through a slit in the black cardboard screen before it. (See Fig. III.) The syllables were all learned by the "Treffer method," and the "Treffer syllables' were shown on this drum, which was turned by the subject as the syllables were required. The syllables to be learned were written on strips of white paper 121⁄2 x 3 inches, ruled with fourteen lines and so proportioned to the drum, that after one complete presentation of the series, two blank spaces were shown before the first syllable of the series reappeared. The odd numbered members of the series-the "Treffer syllables' '-were also written on strips 101⁄2 x 3 inches to fit the smaller drum.

The experiments fell into three series, A, B, and C, and were carried out with two trained observers S and E.

Müller u. Schumann: Experimentelle Beiträge zur Untersuchung des Gedächtnisses, Zeit. f. Psych., VI, 1893-94, 106.

2 The series were prepared throughout the greater part of the work by a competent assistant not otherwise connected with the experiment.