CHAPTER I. 



ARE THERE LAWS OF HEREDITY? 



L 



SCIENCE begins only with the investigation of laws. All that pre- 

 cedes has one only object, to prepare the way for this investigation. 

 Unless we hoped that out of the mass of facts drawn from animal 

 and human psychology, from pathology and history, some fixed 

 and certain rule would arise, our store of materials were valueless, 

 a mere collection of curious anecdotes, which would afford the 

 mind nothing like true science. We believe that the facts we have 

 cited are not to be thus lightly esteemed. It is the privilege of 

 the experimental method which is so often charged with creeping 

 on the ground, with being tied down to facts, and restricted within 

 narrow boundaries without a horizon to reveal to us what is uni- 

 versal, to exhibit to us laws in facts, and to demonstrate for us the 

 seeming paradox, that in the world for the scientific mind there are 

 no facts, but only laws. 



If we take any simple fact of the inorganic world a stone, a 

 liquescent gas, a falling drop of water and consider these pheno- 

 mena, as do people in general, with the eyes and not with the mind, 

 they will be a complete reality, and whatever is not visible and 

 tangible will be but a vain abstraction. But science analyzes these 

 facts into laws of gravity, heat, molecular attraction, affinity, etc., 

 secondary laws which may themselves be referred to more general 

 laws and, perceiving that these laws are found everywhere in the 

 organic world, science concludes that they it is that are real. 

 Group these laws, and we have facts ; group different kinds of laws, 

 and we have' different kinds of facts. It follows that to know a 

 fact thoroughly is to know the quality and the quantity of the laws 

 which compose it, to know that a given fact is resolvable into 

 given laws of heat, gravity, etc., and into a given amounl of heat, 

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