2 28 THE POPULAR SCIENCE MONTHLY 



can be reached by induction alone. Invention of hypotheses, deduction 

 of consequences, and so on, all have their share in reaching such a con- 

 clusion; hence even if an inductive order is adopted in approaching 

 the conclusion, the whole evidence for it can not be set forth in this way. 

 A full demonstration of such a conclusion must necessarily involve some 

 other processes than pure induction. If the presentation appears to be 

 purely inductive, the hearers will have a right to infer that certain 

 important steps have been tacitly passed over ; and the speaker may feel 

 sure that if such omissions are detected by any of his hearers, they will 

 form an unfavorable opinion, because of his want of candor or of 

 thoroughness. 



The Analytical Method. — This method is characterized by the pres- 

 entation, at least in outline, of the successive steps that have led the 

 investigator from his original field of observation to the invention of 

 various hypotheses, to the recognition of the most successful hypothesis, 

 and if possible to its establishment as a verified theory, following the 

 plan set forth in the earlier part of this essay. This method is 

 therefore most appropriate in the presentation of complicated prob- 

 lems which demand much theoretical supplement to observation, in 

 the exposition of problems regarding which various unlike opinions have 

 been held by different investigators, and before hearers who are fully 

 able to appreciate rigorous scientific discussion. The essential feature 

 of this method of presentation is that it should preserve the demonstra- 

 tive quality of the investigation that it represents, and that it should 

 proceed in such an order that the hearers may form a critical opinion as 

 to the value of the conclusion reached at its end. Hence, just as in the 

 usual presentation of a geometrical problem, so in an analytical presenta- 

 tion of a geographical problem, the conclusion or theorem to which the 

 demonstration leads, is advisedly stated not only at the end, but also 

 at the opening of the speaker's address, in order that the hearers may 

 bear it in mind while observed facts, invented hypotheses, deduced con- 

 sequences, and so on, are all set forth in proper sequence. Only 

 when thus aided by being told the end at the beginning can hearers, 

 who are not familiar with the problem under discussion, really form a 

 competent and critical opinion as to the thoroughness with which it has 

 been investigated. 



In view of the short time at a speaker's disposal, the analysis of a 

 complicated investigation can of course be presented only in abstract; 

 but by careful selection of the chief points, it is possible not only to set 

 forth in analytical fashion the leading facts and the most important 

 hypotheses, but also, by impartially confronting the consequences with 

 the facts, to exhibit with convincing clearness the grounds for the final 

 acceptance of one hypothesis and the rejection of its competitors. It 

 should be recognized that while a speaker is thus concerning himself 

 largely with the discussion of past processes, he is for the time being a 



