FREE BOOKS

Author's List




PREV.   NEXT  
|<   237   238   239   240   241   242   243   244   245   246   247   248   249   >>  
ta. Suppose a person were to institute a home for lost dogs, he would doubtless try to ascertain how many dogs were likely to go astray, and in so doing would be guided by statistics. But in judging of the probability of the straying of a particular dog, he would pay little heed to statistics as determining the chances, but would proceed upon empirical knowledge of the character of the dog and his master. Even in betting on the field against a particular horse, the bookmaker does not calculate from numerical data such as the number of horses entered or the number of times the favourite has been beaten: he tries to get at the pedigree and previous performances of the various horses in the running. We proceed by calculation of chances only when we cannot do better. [Footnote 1: _Empirical Logic_, p. 556.] [Footnote 2: Mr. Jevons held that all inference is merely probable and that no inference is certain. But this is a purposeless repudiation of common meaning, which he cannot himself consistently adhere to. We find him saying that if a penny is tossed into the air it will _certainly_ come down on one side or the other, on which side being a matter of probability. In common speech probability is applied to a degree of belief short of certainty, but to say that certainty is the highest degree of probability does no violence to the common meaning.] CHAPTER X. INFERENCE FROM ANALOGY. The word Analogy was appropriated by Mill, in accordance with the usage of the eighteenth century, to designate a ground of inference distinct from that on which we proceed in extending a law, empirical or scientific, to a new case. But it is used in various other senses, more or less similar, and in order to make clear the exact logical sense, it is well to specify some of these. The original word [Greek: analogia], as employed by Aristotle, corresponds to the word Proportion in Arithmetic: it signified an equality of ratios, [Greek: isotes logon]: two compared with four is analogous to four compared with eight. There is something of the same meaning in the technical use of the word in Physiology, where it is used to signify similarity of function as distinguished from similarity of structure, which is called homology: thus the tail of a whale is analogous to the tail of a fish, inasmuch as it is similarly used for motion, but it is homologous with the hind legs of a quadruped; a man
PREV.   NEXT  
|<   237   238   239   240   241   242   243   244   245   246   247   248   249   >>  



Top keywords:

probability

 

proceed

 
inference
 

common

 

meaning

 

similarity

 

horses

 
chances
 
empirical
 

compared


number

 

certainty

 

analogous

 
degree
 

statistics

 

Footnote

 

distinct

 
extending
 

senses

 

similar


scientific

 

INFERENCE

 

ANALOGY

 

CHAPTER

 

violence

 

belief

 
highest
 

Suppose

 

Analogy

 

eighteenth


century

 

designate

 

accordance

 

appropriated

 

ground

 

analogia

 

function

 

distinguished

 

structure

 

called


signify

 
technical
 

Physiology

 

homology

 

quadruped

 
homologous
 

motion

 

similarly

 

original

 

applied