CHANCE, a name under which are classified events the occurrence of which cannot be computed by application of known natural law. Events are referred to «chance» in acknowledgment at once of causality, and of ignorance which restricts us to the statement,—»they happened.» An event or series of events which seems to be the result neither of a necessity inherent in the nature of things, nor of a plan conceived by intelligence, is said to happen by chance.
| Chance is opposed to law in this sense, viz., that what happens according to law may be predicted, and counted on. But everything has its own law and its proper cause; and chance merely denotes that we know not the proper cause, nor the law according to which a phenomenon occurs. So Aristotle says:—» According to some, chance is a cause not manifest to human reasoning.» Δοκεῑ μὲν αἰτία ἡ τύχη, ἄδηλον δὲ ἀνθρωπίνῃ διανοία (Phys., II. 4). Nothing can be more true than Aristotle’s saying (Phys., lib. II.), that if there were no end intended, there could be no chance. |
«It is strictly and philosophically true in nature and reason, that there is no such thing as chance or accident; it being evident that these words do not signify anything that is truly an agent or the cause of any event; but they signify merely men’s ignorance of the real and immediate cause» (Samuel Clarke, ser. XCVIII.; vol. VI. ser. XIII., ed. 1735).
«Chance is usually spoken of in direct antithesis to law; whatever, it is supposed, cannot be ascribed to any law, is attributed to chance. It is, however, certain that whatever happens is the result of some law, is an effect of causes, and could have been predicted from a knowledge of the existence of those causes, and from their laws… An event occurring by chance may be described as a coincidence from which we have no ground to infer an uniformity; the occurrence of a phenomenon in certain circumstances, without our having reason on that account to infer that it will happen again in those circumstances. This, however, when looked closely into, implies that the enumeration of the circumstances is not complete. Whatever the fact be, since it has occurred once, we may be sure that if all the same circumstances were repeated, it would occur again» (J. S. Mill, Logic, bk. III. ch. XVII. sec. 2). «We must remember that the probability of an event is not a quality of the event itself, but a mere name for the degree of reason, we, or some one else, have for expecting it» (ib., ch. XVIII).
«Probability has reference partly to our ignorance, partly to our knowledge. We know that among three or more events, one, and only one, must happen, but there is nothing leading us to believe that any one of them will happen rather than the others… The theory of chances consists in reducing all events of the same kind to a certain number of cases equally possible, that is, such that we are equally undecided as to their existence; and in determining the number of these cases which are favourable to the event of which the probability is sought. The ratio of that number to the number of all the possible cases, is the measure of the probability; which is thus a fraction, having for its numerator the number of cases favourable to the event, and for its denominator the number of all the cases which are possible» (Laplace, Essai Phil. sur les Probabilités, 5th ed., p. 7; Hume, Essay on Probability).— V. AVERAGES.
