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A further use of the word chance is made when we refer to 

 future events, over the circumstances of which we have no 

 control. When we say, " Leave it to chance/' what do we 

 mean? Simply this; that although by our previous knowledge 

 of certain laws we might construct a proper deduction upon 

 them, in accordance with which we might predict the future 

 event, — in other words, expect the same result to follow after a 

 repetition of the same circumstances ; yet we know not but that 

 certain other events or causes might intervene to subvert or 

 alter the strict fulfilment of those known laws. Therefore we 

 cannot be sure of the ultimate result, and we express our inca- 

 pacity by saying we must leave the issue to chance. 



The difference, therefore, between the case of a plant ripening 

 its fruit and a die falling from the box is this : in the former 

 case, without knowing what the laws are which govern the 

 plant, we see the same result constantly recurring under the 

 same circumstances ; and this reduces itself to inductive law, 

 while we presume tacitly that the same secondary causes are 

 brought into play every time we see the same result occurring. 

 But when we throw a die, we can form no inductive law in 

 obedience to which the die will always appear with the ace 

 uppermost. Experience tells us that however nearly in the 

 same way we may shake the box and throw it out, we cannot 

 calculate upon any particular face being uppermost ; we may 

 arrive at some degree of probability, but no certainty. So that 

 we apply the word chance to those results for which we can 

 trace no inductive law. And this brings us to consider its 

 application in nature as concerning the conditions of existence 

 for any individual organism. 



Observation clearly shows that a plant or an animal is not 

 always, if ever, placed under conditions best suited to it. Its 

 position in the world is due to chance; or at most it can be 

 only said to live where its existence is possible, not where con- 

 ditions are most favourable. Now this is the average condition 

 of things, and we may remember that although circumstances 

 affecting the individual may seem to occur capriciously, yet 

 when a large number are examined, law is perceptible as govern- 

 ing the averages. Thus, a large array of facts connected with 

 social life seem, when isolated, to be due to chance, and subject 

 to no law ; yet when they are classified and averages obtained, 

 it is found that these averages are not only subject to law, but 

 such laws as can be practically acted upon, though individual 

 cases may seem to belie the deduction. It is on this principle 

 that the tables of life assurances are constructed, which are 

 expressive of the laws which govern the rates of mortality. 



In nature, then, we place under the head of chance all results 



