Hence it is that we instinctively judge it impossible, or little less than impossible, to cause a determinate effect, by a fortuitous combination; as, for example, to form a page of Virgil by a chance mixture of types, or to hit the bull's eye of a target without taking aim, and other similar things. In this there is assuredly a philosophical reason, but one not known to common people. There is evidence of this reason in the theory of probabilities: it is a distinct application of the principle of causality, and of the natural opposition of our understanding to supposing an effect without a cause, and order where there is no ordering intelligence. 323. Arguments of analogy, are in human life necessary in infinite cases. How do we know that the sun will rise to-morrow? By the laws of nature. How do we know that these will continue in force? Evidently, we must finally recur to analogy. The sun will rise to-morrow, because it has risen to-day; it rose yesterday, and it has never failed to rise. How do we know that spring will again bring flowers, and autumn fruits? Because it has so happened in former years. Men ordinarily do not know the reasons which might be given for founding the argument from analogy on the constancy of the laws of nature, and on the relation between certain physical causes and determinate effects; but their assent is required and given. 324. In all the cases cited, excepting, perhaps, that of immediate evidence, the inclination to assent may be, and really is, called _common sense_. The reason of this exception is, that in this case, although there is no demonstration, the predicate is nevertheless most clearly seen contained in the idea of the subject; but in the other cases there is neither demonstration nor this vision. Man assents by a natural impulse; and if any thing is objected to his belief, he does not call attention to his conception, as in immediate evidence, but is completely disconcerted, and knows not what to answer; he then applies to the objection, not the name of error, nor of absurdity, but that of extravagance, of something contrary to common sense. Suppose, for example, a little grain of sand to be mixed with a great heap, and some one to come and say: I will put my hand into the heap, and instantly draw out the one grain hidden there. What will you object to such a one? What will the beholders reply? Nothing; or, looking at each other in perfect surprise, they will exclaim: "What extravagance! He has no common sense!" Or suppose some one to say, that all we see is nothing, that there is no external world, that we have no body, or that all told us of the existence of a city called London is untrue. Whoever hears such madness, knows not what to answer; but he repels it by a natural impulse, and the mind feels that this is nonsense without stopping to examine.