64 A. F. RAVENSHEAR: beginning. It is not, indeed, explicitly laid down that every man must be his own Observer, Speculator, Experimenter, Calculator, and Critic. The complex interchange of opinion, observations, experimental results, criticisms the division of labour that constitutes the life of science, is simply dropped out of sight. Testimony finds its chief use in the establishment of in- dividual facts. A line of reasoning may be reinvestigated ; an experiment may be repeated. But for knowledge of specific facts or events in the past, or occurring outside one's personal range, each is perforce largely dependent on testimony. Such knowledge must in great part be derived from persons present at the particular time and place of the occurrence. In the current descriptions of the method by which individual facts may be logically proved, the use of testimony is, however, scarcely referred to. In Mill's Logic, for instance, the method is thus described : 1 " When the phenomenon is within the range of present observation, by observation we assure ourselves of its existence ; when it is beyond that range and is therefore said to be absent, we infer its existence from marks or evidences. . . . The simple existence ... is inferred from some inductive law . . . we prove the existence of a thing by proving that it is connected by succession or coexistence with some known thing." It would be a somewhat forced interpretation of this passage to suggest that it covers the case of testimony as to a matter of fact. It might, perhaps, be said that the testimony itself is some known thing connected by succession or coexis- tence with the fact it reports ; and that the inductive laws to which reference is made are laws relating to the condi- tions of trustworthiness of testimony. But to argue thus would seemingly be to adopt as a guiding principle the oft- quoted aphorism that ' language is given us to conceal our thoughts ' ; for even if enclosed in the passage cited, the idea can scarcely be said to be disclosed. In an indirect manner Testimony is doubtless alluded to in Mill's discussion of the " grounds of disbelief " ; 2 and in the dictum " whatever contradicts a well-grounded induction is to be disbelieved ". But this alone is not sufficient. We ought to determine not only what testimony must be re- jected, but under what conditions it may be accepted. Be- tween these two is a broad neutral zone within which we can do nothing but suspend judgment. It seems likely too that some logicians have regarded 1 Chap. xxiv., 1. 2 System of Logic, chap. xxv.
