20 On the present state of Zoology. 



himself can distinctly appreciate ; that, at any rate, points, with respect 

 to which there exists any ground for difference of opinion, can hard- 

 ly be advanced in proof of a theory, whatever there may be to render 

 that theory probable. 



In fact, we believe the time is not yet come, in which it is possible 

 to demonstrate the truth of any theory whatever. We may shew the 

 apparent influence exerted by certain principles which seem capable of 

 being deduced from the data already in our possession ; but we con- 

 ceive that we must be more acquainted with the structure and affini- 

 ties of animals, before we can establish such principles upon a sure 

 basis. Nevertheless, we would not discourage persons from making 

 the attempt. We are rather inclined to let all naturalists hold their 

 own opinions on this subject, convinced that truth will work its way 

 in the end, and that, if not found in exact agreement with what they 

 had anticipated, it will at least have received some light from their 

 researches. 



In the meanwhile, those who keep aloof from speculations of the 

 above kind should endeavour to enlarge the bounds of our positive 

 knowledge as regards this science. Let them investigate some of 

 those departments, to which so little attention has been as yet given, 

 and try to place the several ramifications of the great system of na- 

 ture upon a more equal footing. By so doing, they will supply sound 

 materials for such as choose to speculate upon the exact plan on which 

 that system is constructed, at the same time that they help the science 

 forwards to that point, which, when arrived at, the plan will in some 

 measure develop itself. For it should be remembered, that there are 

 two distinct objects to be attained, as regards the natural system : — 

 " first, the arrangement of all animals according to their true rela- 

 tions ; and then the discovery of those general principles (assuming 

 that there are such) by which these relations are governed."* Now 

 had we already effected the first of these objects, which can only be 

 the result of a rigid analysis, extended to all the groups of animals 

 with which we are acquainted, we should probably have little difficul- 

 ty in evolving the latter. At present, however, this has been but 

 very imperfectly done. And, perhaps, we are more likely to proceed 

 rightly in this matter^ when we go to work, unfettered by any theo- 

 retical views, which in our anxiety to uphold, we are liable to have 

 our judgment biassed to a degree to which we ourselves are totally 

 unconscious. It is, undoubtedly, at all times agreeable to true philo- 

 sophy to ascend by inductive reasoning from known facts to general 



* The above passage will be found nearly similar to what Mr Swainson has 

 expressed at p. 200 of his Preliminary Discourse. 



