Page:Mind (Old Series) Volume 12.djvu/498

 NOTES. 485 perceptions of equilibrium between diverse probabilities and utilities, evidence more analogous to the physicist's * observations ' than to his reasoning. The quantities to which the Theory of Observations is applied in Physics are times, distances, and the like. The quantities which are the objects of the analogous method in Social Science are partly indeed objective : as when we compare the opinions of authorities on Currency as to the amount of wealth likely to result from the adoption of Bimetallism. But the Utilitarian is concerned with ends as well as means. In considering, for instance, the policy of Trades-unions, he must not only estimate their effect upon wages or production, but also weigh the opinion which, according to Prof. Sidgwick, is wide-spread "among observant persons, that human beings generally have a tendency to overvalue leisure as a source of happiness ". The indeterminateness which blurs our estimate of hedonic quantities may be reduced to a minimum by the combination of judgments with due regard to their weight. Prof. Sidgwick doubts " whether a mere increase of numbers of human beings, living as an average unskilled labourer lives in England, can be regarded as involving material increase in the quantum of human happiness". So the physicist may doubt whether a transit observed by him occurred at a particular time, or at an epoch earlier, say, by a tenth of a second. The error, so considerable while we rely upon a* single judgment, is reduced by the combination of observations. Thus the higher branch of Probabilities projects into the field of Social Science. Conversely, the principle of Utility is at the root of even the more objective portions of the Theory of Observations. The founders of the science, Gauss and Laplace, distinctly teach that, in measuring a physical quantity, the quassitum is not so much that value which is most probably right, as that which may moat advantageously be assigned taking into account the frequency and the seriousness of the error incurred (in the long run of metretic operations) by the proposed method of reduction. The writer has attempted, in the work referred to, to state these prin- ciples with more qualification and with greater clearness than the brevity of the present communication admits. He has aimed at portraying the philosophic aspect of the Calculus of Probabilities in a manner intelligible to the generally-educated man. The reflections, which cannot be appre- hended without a technical knowledge of the Method of Least Squares, have been relegated to an Appendix. R Y. EDGEWORTH. In the Vierteljahrsschrift fur ivissenschaftliche Philosophic xi. 2 (April, 1887), Dr. F. Koerber criticises Prof. Bain's views as to the mechanical correlates of mental reproductions. He agrees with Prof. Bain that the correlates of original and reproduced mental processes are, intensity apart, identical, but contends that they must be sought entirely in the brain ; mental reproductions being in no way correlated with the diffusion of a current of nervous energy upon the peripheral organs. He examines in detail Prof. Bain's arguments in The Senses and the Intellect (3rd ed., p. 377), concluding in every case that the facts brought in support of the hypo- thesis of a correlation of consciousness with the whole nervous process, instead of simply with the process in the brain, admit of some other explanation. He also brings some objections against the admissibility of the hypothesis in itself. For example, he remarks that if ideas of sounds are accompanied by a return current on the organ of hearing, then, since there is a tendency to vocal and other rhythmical accompaniments of remembered tune?, the hypothesis requires that the original process of hearing a tune should be correlated with vocal and respiratory as well as