This would seem to be the place to institute further studies. Our consciousness conveys to us from within not only the sensations of pleasure and ‘pain’, but also those of a peculiar tension, which again may be either pleasurable or painful in itself. Now is it the ‘bound’ and ‘unbound’ energy processes that we have to distinguish from each other by the help of these sensations, or is the sensation of tension to be related to the absolute quantity, perhaps to the level of the charge, while the pleasure-pain series refers to the changes in the quantity of charge in the unit of time? We must also be struck with the fact that the life-instincts have much more to do with our inner perception, since they make their appearance as disturbers of the peace, and continually bring along with them states of tension the resolution of which is experienced as pleasure; while the death-instincts, on the other hand, seem to fulfil their function unostentatiously. The pleasure-principle seems directly to subserve the death-instincts; it keeps guard, of course, also over the external stimuli, which are regarded as dangers by both kinds of instincts, but in particular over the inner increases in stimulation which have for their aim the complication of the task of living. At this point innumerable other questions arise to which no answer can yet be given. We must be patient and wait for other means and opportunities for investigation. We must hold ourselves too in readiness to abandon the path we have followed for a time, if it should seem to lead to no good result. Only such ‘true believers’ as expect from science a substitute for the creed they have relinquished will take it amiss if the investigator develops his views further or even transforms them. For the rest we may find consolation in the words of a poet for the slow rate of progress in scientific knowledge: Whither we cannot fly, we must go limping. · · · · · The Scripture saith that limping is no sin.[37] INDEX Acquired instinctive dispositions, 49. Adaptation, 52. Death a phenomenon of, 58. Ambivalence, hate-love, 69. Amphimixis, 60, 72. Anabolic processes, 63. Angst, 9. Animalculae, 60, 61. Anxiety dreams, 38. Apprehension, 9, 37, 39. _Aristophanes_, 74. Barrier against stimuli, 33, 34, 36–7. Binding, psychical, 30, 34–7, 39, 42, 44, 80–2. _Breuer, J._, 10, 27, 30, 36, 42. _Calkins_, 60. Charge, 34–7, 80, 82. Breuer’s bound or tonic, 42. Counter-, 34. Free-flowing, 36, 42, 80. of object, 64. Over-, 37, 39–40. Quiescent, 35–6, 80. Children, play of, 11, 16, 43. Compulsion, 22, 49. Daemonic, 44. Destiny-, 24. Repetition-. _See_ Repetition-compulsion. to repeat, 44. Conjugation, 60, 63, 71–3. Conscious: Becoming, 27, 28. ego, 19–20. impulses, 3. psychic processes, 32. The, 19.