A CRITICISM. 13 



our present acquaintance with that subject we know that it has some rela- 

 tion to the position and mass of the earth, including its ocean tides; also 

 to the position and mass of the sun ; also to the position and mass of 

 every one of the planets; also of the comets, numerous and unknown as 

 they are ; also the meteoric rings ; and finally of all the stars ! The 

 problem, as everyone knows, is absolutely insoluble even for the shortest 

 period ; but when the element of Time enters in, and we consider that 

 to do anything like justice to the problem in an astronomical sense we 

 should have to solve it for at least a million years during which interval 

 the earth, sun and other bodies concerned would themselves have been 

 changing their relative positions, it becomes obvious that the whole ques- 

 tion is infinitely complex and yet this is only a small fragment of Astron- 

 omy. To debate, therefore, whether the infinite complexity of the move- 

 ments of the stars is greater or less than the infinite complexity of the 

 phenomena of life, is like debating the precedence of the three persons 

 of the Trinity, or whether the Holy Ghost was begotten or proceeding : 

 we are talking about things which we do not understand. 



Nature is one; she is not, we may guess, less profound and wonderful 

 in one department than another; but from the fact that we live under 

 certain conditions and limitations we see most deeply into that portion 

 which is, as it were, on the same level with us. In humanity we look 

 her in the face; there our glance pierces, and we see that she is profound 

 and wonderful beyond all imagination; what we learn there is the most 

 valuable that we can learn. In the regions where Science rejoices to 

 disport itself we see only the skirts of her garments, so to speak, and 

 though we measure them never so precisely, we still see them and nothing 

 more. 



There is another point, however, of which much is often made as a 

 plea for the substantial accuracy of the scientific laws and generalisations, 

 namely that they enable us to predict events. But this need not detain us 

 long. J. S. Mill in his " Logic" has pointed out and a little thought 

 makes it obvious that the success of a prediction does not prove the 

 truth of the theory on which it is founded. It only proves the theory was 

 good enough for that prediction. 



There was a time when the sun was a god going forth in his chariot 

 every morning, and there was a time when the earth was the centre of the 

 universe, and the sun a ball of fire revolving round it. In those times 

 men could predict with certainty that the sun would rise next morning, 

 and could even name the hour of its appearance ; but we do not there- 

 fore think that their theories were true. When Adams and Leverrier 

 foretold the appearance of Neptune in a certain part of the sky, they made 

 a brief prediction to an unknown planet from the observed relations of 

 the movements of the known planets ; that does not show however that 

 the grand generalisation of these movements, called the " law of gravita- 

 tion," is correct. It merely shows that it did well enough for this very 



