{25} It is easy for an observer to detect intellectual necessity in judgment, even where the judging subject is wholly unreflective. If you contradict an obvious judgment made by an uneducated man, he will no doubt be quite unable to point out the intellectual necessity which constrains him to it, _i.e._ to argue in support of it; but he will be bewildered and probably indignant, which shows that, unknown to himself, his whole intellectual existence is really impeached by impeachment of a necessary conclusion from it. Many people cannot see the difference between impeaching their argument and impeaching their veracity; and this confusion arises, I presume, from a just feeling that their whole mind is on its trial in the one case as in the other, although they do not distinguish between the forms of its action which are concerned. We are told, indeed, in formal logic, that ordinary statements of fact do not claim necessity; but this merely arises from confining necessity to explicit necessity expressed in a special grammatical form. But, it may be objected, we do not always feel that every trivial judgment emanates from and so implicates our whole mental constitution and equipment. If I say to a friend, “I saw you at Charing Cross yesterday,” and he says, “No, you could not, for I was out of town,” then, unless I was very certain indeed, I should admit having made a mistake, and think no more about the matter. That only means, (1) that the unity of the mind is not thoroughly complete--there are many more or less detached systems in the mind, and one of them may not be very deeply inwrought in the whole intellectual frame; and (2) the necessity of thought may itself modify the certainty of the fact, _e.g._ I know that {26} a mistake of identity is quite a common thing, and this knowledge co-operates with my friend’s denial. But in any perceptive judgment, however unimportant its immediate content, if it is clear and persistent, a contradiction is a most serious thing. There is a well-known form of bewilderment connected with the judgment of direction; if you forget or do not know of a turn that you have taken, and come out, for example, on familiar ground from the North when you think you are coming on it from the South, so that objects have the reverse position of what you expected, then, supposing that you cannot explain the contradiction, the result is sometimes a very grave perplexity; some men are quite unhinged by it for the moment, and a psychologist in France [1] has given it a new name, “Vertigo of Direction.” This again shows how your whole intellectual nature is staked upon the most trifling perception, and if you seem to be forced to a flat contradiction even in the simplest judgment you are almost “beside yourself.” [1] M. Binet. See _Mind_, x. 156. _Judgment universal_