6zo POPULAR SCIENCE MONTHLY. 



There is what is known as the " balance of natural forces." It 

 is this that keeps the planets balanced in their orbits, and among 

 animals it holds the species within the bounds which make for the 

 greatest happiness of the greatest number. It is the plan of an 

 all-merciful Creator, and man has never been able to suggest an 

 improvement upon it, within the limits of physical conditions. 



From the above, we see that every animal life is cast into the 

 world as an experiment, often of the severest and most painful 

 type. In this lifelong vivisection, Nature provides no ether or 

 chloroform, nor even chloral or morphine. 



By this very dispensation of Nature God clearly gives to man 

 every sanction to cause any amount of physical pain which he 

 may find expedient to unravel his laws. Not only this, the situa- 

 tion places upon man heavy duties, which he is bound to perform. 

 These we will consider in a moment. As far as biological science 

 is concerned the whole argument may be summed up as follows : 

 Biology is not an exact science like mathematics and physics. 

 These sciences are exact simply because it is possible in them to 

 obtain as many equations as there are unknown quantities to be 

 determined. Hence, with the solution of all possible equations, 

 every unknown quantity in these sciences may be exactly deter- 

 mined. In biological sciences the case is thus far quite different. 

 Here the unknown quantities are legion in every equation. 

 Hence the extreme difficulty of any solid advance ; hence the 

 many mistakes, the many disagreements. In the best of experi- 

 ments it is only possible to mass one series of unknown quanti- 

 ties against another series of unknown quantities so that they 

 balance as nearly as possible, and then with our one unknown 

 quantity, about which the experiment turns, make the best tem- 

 porary solution of our problem possible. Thus the science must 

 be content to proceed until the vast series of unknown conditions 

 which influence life have been dealt with one by one. Thus, if 

 the science is to advance, if we are ever to learn under what con- 

 ditions life is most favorably placed, we must vary the conditions 

 in every possible way i. e., experiment physiologically ; and, as we 

 have seen, everything in the divine ordering of Nature is in com- 

 plete harmony with this method, and bids man Godspeed in this 

 great work. 



Thus far we have considered Nature as uninfluenced by the 

 presence of man. Let man, a moral being, take his place among 

 the animal creation, and at once there spring up moral relations 

 between him and every living thing capable of feeling pleasure 

 and pain. It becomes his duty to do all in his power to increase 

 the happiness and to diminish the suffering of every sentient 

 thing. But we do not sympathize with the Hindu who lay down 

 before the starving tigress in order to save her life and the life of 



