An Introduction to a Biology 



not get much further than perception, man goes on to reason 

 about the things he perceives. But you see, of course, that 

 he must perceive the things first, before he can go on to 

 reason about them. 



Now you know that man in his attempts to account for 

 things has repeatedly gone astray. Even those people who 

 are stupid enough to think that the ways in which we account 

 for things to-day are right and true and everlasting are not 

 blind to the fact that the theories by which their predecessors 

 tried to account for things were wrong, false and transient. 

 But we are not concerned with that point now. The point 

 is, we may take it as established that in the second part 

 of the process, in trying to account for things, man has gone 

 hopelessly astray. Are we sure that in the sphere of descrip- 

 tion there is no chink into which error may creep ? Let us 

 make quite sure of this before we see to keeping our machinery 

 of reasoning in order. For unless we are perfectly sure that 

 we see things aright, it is manifestly absurd to try to account 

 for them. We cannot interpret nature until we know what 

 nature is. Our first business is to describe ; when we have 

 done that properly we can go on to explain. We ask our- 

 selves : Has error characterised our description of things 

 to the same extent as it has our attempts to account for 

 them ? And the answer I suggest is : Yes, but in a less 

 degree. 



The question naturally suggests itself : How can we go 

 astray if we merely describe things ? Surely the same thing 

 cannot be two different things at the same time. And the 

 answer I should make to this is that, if one can be sure about 

 anything, one can be sure that a thing cannot be two different 

 things at the same time. But we hardly ever do merely 

 describe things. Practically all description of natural pheno- 

 mena is made with a view to its bearing on some general 

 problem, and the describer is expected to give some pro- 

 nouncement as to the direction in which his work points, 

 whether' it be for or against one or other of current rival 



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