Outlines of Logic Psychology and Ethics Author:Arthur Baker Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: the quality in question and any quality that is common or not common to the two instances, i.e. any point of resemblance or difference; (2) we only reckon gro... more »ups of causally connected qualities as single points of resemblance or difference. The probability of our conclusion will then depend on (1) the numerical ratio of the ascertained points of resemblance and difference to the sum-total of points of resemblance and difference; if we only know about our instances very little of what is to be known about them, the conclusion is invalid; (2) the numerical ratio of the ascertained points of resemblance to the ascertained points of difference; in proportion as the former exceed the latter, the conclusion is strengthened. The argument from analogy is, therefore, neither an induction per enumerationem simplicem nor an induction proper; for it does not argue from the number or character of the instances in which one common quality is found, but from the number of common qualities found in two instances. The chief value of analogy lies in the fact that it suggests applications of true inductive methods. Question 19, Distinguish between Observation and Experiment, giving the advantages of each. By what rules should they be guided ? a. In Observation the circumstances amidst which aphenomenon appears are found varied; in Experiment we make them varied. Thus in the study of Astronomy we watch, but cannot control, the motions of the planets; but in the study of Chemistry we can introduce at pleasure a new phenomenon into a group already known. b. The advantages of Observation are that it is the only process whereby (1) we can study such sciences as Astronomy and Physiology, where experiments are impracticable; (2) we can reason from effect to cause; ...« less