68 Education through Nature 



of horses we finally get the general idea that all horses 

 neigh, perhaps; or that all horses have a mane. Or 

 more definitely : Monday, Tuesday, Wednesday, Thurs- 

 day, Friday, Saturday, and Sunday contain less than 

 twenty-five hours. These are all the days of the week; 

 therefore all the days of the week contain less than 

 twenty-five hours. 



Induction is the mode by which all the materials of 

 knowledge enter the mind, and are analyzed. It is 

 sometimes defined as inference from the known to 

 the unknown ; or, as passing from the concrete to 

 the abstract. 



The disadvantages of this method are: (i) It re- 

 quires sound sense-organs; (2) physical strength 

 besides mental activity; (3) states of consciousness 

 may affect the peripheral sense-organs; (4) it is a 

 slow and laborious method. It requires less effort 

 to assume the truth of a general proposition, and then 

 to proceed to draw conclusions about everything 

 included in that general, than to carefully examine 

 each particular thing individually, and, from many 

 such examinations, to draw general conclusions. The 

 inductive method suggests the laboratory, with all 

 its arduous work; while the deductive method sug- 

 gests the drawing-room and the easy-chair, possibly 

 the library. (5) Unless all particulars are thus exam- 

 ined, general conclusions may not be absolutely true. 



Consequently there are: (a) perfect induction (all 

 particulars examined) ; (6) imperfect induction (only a 

 large number of particulars examined). Perfect in- 

 duction is sometimes said to be no induction at all, 

 because, if all particulars are examined, there is no 

 gain from an inference, all being gained through 

 experience. The object of an inference is to pass 

 beyond what can be immediately perceived. 



The advantages of induction are gained from the 

 imperfect induction referred to above. A perma- 



