In opinions of long continuance, and in which we have never before been molested by a single doubt, to be suddenly convinced of an error, is almost like being convicted of a fault. There is a state of mind, which is the direct antithesis of that, which takes place when we make a bull. The bull namely consists in the bringing her two incompatible thoughts, with the sensation, but without the sense, of their connection. The psychological condition, or that which constitutes the possibility, of this state, being such disproportionate vividness of two distant thoughts, as extinguishes or obscures the consciousness of the intermediate images or conceptions, or wholly abstracts the attention from them. Thus in the well known bull, ‘I was a fine child, but they changed me:’ the first conception expressed in the word ‘I,’ is that of personal identity—Ego contemplans: the second expressed in the word ‘me,’ is the visual image or object by which the mind represents to itself its past condition, or rather, its personal identity under the form in which it imagined itself previously to have existed,—Ego contemplatus. Now the change of one visual image for another involves in itself no absurdity, and becomes absurd only by its immediate juxta-position with the fast thought, which is rendered possible by the whole attention being successively absorbed to each singly, so as not to notice the interjacent notion, changed, which by its incongruity, with the first thought, I, constitutes the bull. Add only, that this process is facilitated by the circumstance of the words ‘I’, and ‘me’, being sometimes equivalent, and sometimes having a distinct meaning; sometimes, namely, signifying the act of self-consciousness, sometimes the external image in and by which the mind represents that act to itself, the result and symbol of its individuality. Now suppose the direct contrary state, and you will have a distinct sense of the connection between two conceptions, without that sensation of such connection which is supplied by habit. The man feels as if he were standing on his head though he cannot but see that he is truly standing on his feet. This, as a painful sensation, will of course have a tendency to associate itself with him who occasions it; even as persons, who have been by painful means restored from derangement, are known to feel an involuntary dislike towards their physician.’Now, making a bull’ (also called ‘making an Irish bull’) meant uttering, without realising your own illogicality, an incongruent or ludicrous statement. The derivation of the phrase is unclear, but may be related to the Middle English sense of ‘bull’ as a verb meaning ‘befool, mock, or cheat’. The phrase in this sense was first used of Irish politician Boyd Roche (1736-1807), who is reputed to have said during parliamentary debate: ‘Why we should put ourselves out of our way to do anything for posterity, for what has posterity ever done for us?’ Coleridge was particularly fascinated by bulls (in this sense); there are multiple discussions of the phenomenon in his notebooks.
Now this is the new thing, that nobody spotted before: the source of ‘the well known bull, I was a fine child, but they changed me.’ Coleridge found this phrase in James Gregory’s ‘A Dissertation on Bulls’, in Philosophical and Literary Essays (2 vols 1792)—although Coleridge may have come across it not in the published volume, but in The Universal Magazine 91 (1792), 105-06, where this particular essay was excerpted. Gregory gives several examples of ‘bulls'.
We hear and read of many wonderful bulls of the truly practical kind, altogether independent of language, and plainly founded in thought alone; such as, sending express for a physician to come without delay to a patient who was in the utmost danger, and telling the doctor, in a postscript of the letter addressed and actually sent to him, not to come, as the patient was already almost well again; or observing gravely, when this story was told, that it was right to add such a postscript, as it saved the sending another express to countermand the doc tor; or inclosing a thin sixpence in a snuff-box, that it might not be again to seek when it was wanted to open the box, the lid of which was stiff; or realising Hogarth's ingenious emblem, in one of his election-prints, by cutting away close to the tree the bough on which the person who cut it sat himself; which I once saw successfully performed; and, for the honour of my own country, I must say that it was in Scotand, and by a Scotchman, who narrowly escaped breaking his neck by so doing.... before concluding with what he calls ‘the maximum of bulls, and instar omnium [representative of the whole]’:
A gentleman, when his old nurse came begging to him, harshly refusing her any relief, and driving her away from his door with reproaches, as having been his greatest enemy, telling her that he was assured he had been a fine healthy child till she got him to nurse, when she had changed him for a puny sickly child of her own. If I am rightly informed, France has the honour of having produced this immense and unparalleled bull; which is indeed perfectum expletumque omnibus suis numeris et partibus [‘perfect in all its details and emblematic of the larger whole; Cicero De natura deorum 2:13], and perfect of its kind.It's almost too exciting! It’s clear from this that Coleridge’s ‘I was a fine child, but they changed me’ means: I was a healthy child but then I was physically replaced by a sickly changeling’, rather than (as I have sometimes seen in critical discussion of the passage) ‘I was a fine child but childhood, or "they", altered me for the worse’.