I must restrict myself to this one instance. In Breuer and Freud's book there is a wealth of similar examples. It is easy to understand that scenes such as these make a very strong impression, and accordingly there is an inclination to attribute a causal significance to them in the genesis of the symptoms. The then current conception of hysteria, arising from the English "nervous shock" theory, which Charcot strongly supported, came in conveniently to elucidate Breuer's discovery, hence arose the _trauma-theory_ maintaining that the hysterical symptom and in so far as the symptoms comprise the disease, hysteria itself, arises from some _psychic injury_ (or _trauma_), the effect of which is retained in the unconscious indefinitely. Freud, working as Breuer's colleague, amply confirmed this discovery. It was fully demonstrated that not one out of the many hundred hysterical symptoms came down ready made from heaven; they had already been conditioned by past psychic experiences. To some extent, therefore, this new conception opened up a field of very important empirical work. But Freud's tireless spirit of inquiry could not long rest content at this superficial layer, since already there obtruded deeper and more difficult problems. It is obvious enough that moments of great fear and anxiety, such as Breuer's patient went through, would leave behind a lasting effect, but how is it that these happenings are themselves already deeply stamped with the mark of morbidity? Must we suppose that the trying sick-nursing in itself produce such a result? If so, such effects should occur much more frequently, for there are, unfortunately, many trying cases of sick-nursing, and the nurse's nervous constitution is by no means always of the soundest. To this problem medicine gives its admirable answer; the "x" in the calculation is _predisposition_; there is a tendency to these things. But for Freud the problem was, what exactly constitutes this predisposition? This question led logically to an investigation of all that had preceded the psychic trauma. It is a matter of common observation that distressing scenes have markedly different effects upon the different participants, and that things which to some are quite indifferent or even pleasant, such as frogs, mice, snakes, cats, excite the greatest aversion in others. There are the cases of women who can calmly be present at a very bad operation, but who tremble all over with horror and nausea at the touch of a cat. By way of illustration let me give the case of a young lady suffering from severe hysteria following a sudden fright.[224] She had been at a social gathering, and was on her way home at midnight accompanied by several acquaintances, when a carriage came up behind them at full speed. All the others moved out of the way, but she, beside herself with fright, ran down the middle of the road just in front of the horses. The coachman cracked his whip and cursed and swore in vain.