HUMAN NATURE A SUBJECT OF SCIENCE. 527 



CHAPTER HI. 



THAT THERE IS, OR MAY BE, A SCIENCE OF HUMAN NATURE. 



§ 1. It is a common notion, or at least it is implied in many common 

 modes of speech, that the thoughts, tcelings, and actions of sentient 

 beings are not a subject of science, in the same strict sense in which 

 this is true of the objects of outward Nature. This notion seems to 

 involve some confusion of ideas, which it is necessary to begin by 

 clearing up. 



Any facts are fitted, in themselves, to be a subject of science, which 

 follow one another according to constant laws ; although those laws 

 may not have been discovered, nor even be discoveral)lc by our exist- 

 ing resources. Take, for instance, the most familiar class of meteor- 

 ological phenomena, those of rain and sunshine. Scientific intjuiry 

 has not yet succeeded in ascertaining the order of antecedence and 

 consequence among these jilicnomcna, so as to be able, at least in our 

 regions of the earth, to predict them with certainty, or even witli any 

 high degree of probability. Yet no one doubts that the phenomena 

 depend upon laws, and that these must be derivative laws resulting 

 from known ultimate laws, those of heat, vaporization, and elastic 

 fluids. Nor can it be doubted that if we were acquainted witli all the 

 antecedent circumstances, we could, even fi'om those more general 

 laws, predict (saving difficulties of calculation) the state of the weather 

 at any future time. Meteorology, therefore, not only has in itself 

 every natural requisite for being, but actually is, a science ; although, 

 from the difficulty of observing the facts upon which the phenomcMia 

 depend (a difficulty inherent in the peculiar nature of those phe- 

 nomena) the science is still very imperfect ; and were it perfect, might 

 probably be of little avail in practice, since the data requisite for 

 applying its jirinciples to particular instances would rarely be pro- 

 curable. 



A case may be conceived, of an intermediate character between the 

 perfection of science, and this its extremi; imperfection. It may hap- 

 pen that the greater causes, those on which the principal part of a 

 phenomenon depends, are within the reach of obsei'vation and 

 measurement ; so that if no other causes intervened, a complete 

 explanation could be given not only of the })henomenon in general, but 

 of all the variations and modifications wliich it admitted of Jiut inas- 

 much as other, perhaps many other causes, separately insignificant in 

 their effects, cooperate or conflict in many or in all cases with those 

 greater causes ; the effect, accordingly, presents more or less of aberra- 

 tion from what would be produced by the greater causes alone. Now, 

 if these minor causes are not so constantly accessible, or not accessible 

 at all, to accurate observation ; tlu; principal mass of the eflect may 

 still, as before, be accounted f )r, and even predicted ; but tlnire will 

 be variations and modifications which we arc not comnetent to explain 

 thoroughly, and our predictions will not be fulfillea accurately, but 

 only approximately. 



It is thus, for example, with the theory of the tides. No one doubts 

 that Tidology (as Mr. Whewell proposes to call it) Ls really a science. 



