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with intense actual impressions, such as acuteness of touch, and intolerance of light or sound.
To what causes this diversity of action is chiefly owing it is difficult to say. The nerves connected with the production of sensations are never excited but when the organ which they supply comes in actual contact with external matter. On the other hand, the nerves which give rise to ideas do not impart their peculiar influence, unless excited by that ultimate law of the mind, which ordains, that the repetition of a definite sensation shall be followed by a renovation of the past feelings with which it was before associated. If, then, the nerves, which are considered as instrumental to actual impressions or sensations, derive their origin from the external surface of the organ which they supply, and then influence the circulation, various morbid phenomena connected with the state of the memory no less indicate, that to other nerves, the peculiar function of which is the renovation of past feelings, a different origin may with some reason be assignable; that such nerves may first rise from the brain, and be afterwards distributed to each vascular organ. On this hypothesis may be probably explained the curious fact, that in certain morbid affections, the peculiar seat of which is in the brain, ideas only are excited; and hence, that spectral impressions may be unattended by any such increased sensibility of touch, hearing, vision, &c., as is common to ecstatic illusions.
But i may be now asked, Under what circumstances are sensations and ideas conjointly affected by morbific excitements? In attempting an answer to
this question, it is rather difficult to conceive of a cause which, by acting immediately on the whole of the nervous system, can simultaneously vivify both actual and renovated impressions; but it is not so difficult to conceive of an agent, such as the nitrous oxide, which can communicate a general influence to each organ of feeling through the medium of the circulating system, upon the varied condition of which the vividness of sensations and ideas has a more direct dependence. By this means, therefore, an adventitious or morbific agent can prove the substitute for a general nervous influence; and whenever the blood is in this state of excitement, the phenomena of various ecstacies indicate, that while sensations and ideas are severally increased in intensity, the influence upon which the renovation of past feelings depends, is in proportion more freely and forcibly communicated than that which is connected with actual impressions.
There are, again, other circumstances to be considered in the vivifying actions of morbific causes. A true ecstacy, which is characterized by the simultaneous excitement of sensations and ideas, is often persistent. But when ideas are exclusively vivified, the action is seldom continued for a long time without remission. Thus, in a case of delirium tremens, which came under my notice, the intense revivals of past feelings of touch, or the distinct tones of voice which vibrated in the morbid ear, "like no mortal sounds," or the
"Forms without bodies, and impassive air,"
that flitted before the sight, were not uninterruptedly
continued, as during an ecstacy, but impressed the senses with evident remissions. The patient had therefore an opportunity of comparing his phantasies with the place in which he was stationed, and with the objects around him, so as to obviate the force of his illusion by the faculty of judgment. Nicolai possessed the same self-collection. "I was always able," he observes, "to distinguish, with the greatest precision, phantasms from phenomena. I knew extremely well, when it only appeared to me that the door was opened and a phantom entered, and when the door really was opened and any person came in." In many instances, however, the illusion has not been so easily corrected.
Nor do causes which exclusively vivify the recollected images of the mind constantly occupy the entire surface of any particular organ of feeling. It is in general only a few objects in a renovated landscape which usurp corresponding portions of the seat of vision. A detached figure may hold a place among natural and real objects, partaking with them of a similar degree of vividness, and hence be mistaken for an actual impression.
Having at length explained the phenomena by which partial and general excitements are distinguished, I shall, in the ensuing chapters, confine myself to the consideration of those agents which diffuse their influence so generally throughout the system as to act at one and the same moment of time, though in different proportions, both on sensations and ideas, producing what are named ecstatic illusions.
GENERAL MENTAL EXCITEMENTS CONSIDERED AS THE RESULT OF MORBIFIC CAUSES CO-OPERATING WITH MORAL AGENTS.
"For I am sick, and capable of fears."
I HAD occasion to remark in a preceding chapter, that feelings of pleasure and pain acknowledge certain innate laws, which may be regarded as arising from the particular constitution of the human frame. Thus, it is implanted in our nature, that certain external objects, as of touch, sound, colour, taste, smell, &c. should communicate to every individual definite pleasurable or painful effects.
The particular susceptibility of feeling, however, possessed by each part of the body, may materially differ in degree; and this difference may result from the extent of influence imparted by the brain and nerves to the various organs of sense, or it may arise from some particular condition of the organs themselves, by which the mental effect resulting from the nervous system is more or less modified. Nay, more— such various susceptibilities of feeling may even be occasioned by some unknown peculiarity of the im
material mind itself, by which, in its relation to the structure of the human frame, it is rendered more liable to one particular state than to another. From any one, therefore, of these several causes, or even from a co-operation of two or more of them, there may, in the same person, be an innate tendency to receive a more vivid degree of pleasure from sound than from colour; or a degree of vividness, no less disproportionate, may be imparted to the sensations connected with the gustatory organs. Even with regard to feelings of the same kind, a variety of predilections may subsist. One tint of colour or shade may naturally give more delight than another, and the same observation may apply to particular odours, tones, &c. Lastly, this constitutional variety of susceptibilities evinced in the several organs of the body, may again differ in different individuals.
In the next place, when we contemplate man as a social being, we shall find, that his innate and individual susceptibilities of pleasure or of pain are liable to be still farther modified. Moral laws exist which determine on what occasions of social intercourse particular hopes and fears shall be excited. Such definite occasions are connected with the acquisition or privation of knowledge, of power, of society, of the means of evincing gratitude, of the means of resentment, and of the esteem of our fellow-creatures.
These remarks lead me to attempt the explanation of a very important law, relative to the manner in which the mind may be influenced. A morbific cause, whether pleasurable or painful, can only co-operate with moral agents endowed with a similar specific