506 PROGRESS OF SCIENCE IN THE CENTURY. 



stance by shipwreck, is not a social group, though 

 it might become one. The Pilgrim Fathers, on the 

 other hand, formed a social group. Until there is 

 enough of unity for the group to act, however imper- 

 fectly, as a group, contradicting the egoism of the 

 isolated individual, there is no society. 



The chief objections to the analogy, as it seems to 

 us, are: — (1) that every societary form we know 

 is an imperfectly unified integrate of organisms, and 

 that the analogy is rather between society and ant- 

 hill or bee-hive or beaver-village thaji between a 

 society and an animal body; (2) that the unity which 

 the social philosopher looks for is " a unity which 

 is the end of its parts," but though this is clearly 

 distinct from a mechanical unity, it is rather an ideal 

 than a reality either in society or in an individual 

 body; and (3) that since the biologist haiS not yet 

 been able to discover the secret of the individual 

 organism, notably the secret of its unity, the compar- 

 ison is suggestive of an attempt to interpret ohscurum 

 per ohscurius. 



In thinking of the unity of the individual organ- 

 ism — which seems to us an unsolved problem — we 

 have to distinguish (a) the physical unity which 

 rests on the fact that all the component units are 

 closely akin, being lineal descendants of the fertilised 

 ovum, and on the fact that they are subtly con- 

 nected with eajch other, Avhether by intercellular 

 bridges or by the commonalty estalDlished by the 

 vascular and nervous systems; and (b) the psychical 

 unity, the esprit de co7'ps, which in a manner incon- 

 ceivable to us makes the whole body one. There are 

 organisms, like sponges, in which the psychical unity 

 cannot be verified. 



The same is true in regard to the social organism ; 



