LIFE AND HABIT 95 



and they only serve us because it suits their purpose to do so, as long as 

 we serve them. Who shall draw the line between the parasites which 

 are part of us, and the parasites which are not part of us ? Or again, 

 between the influence of those parasites which are within us, but are yet 

 not us, and the external influence of other sentient beings and our fellow- 

 men ? There is no line possible. 



This passage, then, raises the all-important question of bio- 

 logical relatedness, and it is well calculated to show how greatly 

 the understanding of Pan-Psychism depends upon " Qualitative 

 Biology." I have already emphasised the need of a qualitative 

 Biology and in particular of the inauguration of a standard of 

 biological usefuless with the aid of which to sift the grain of 

 wholesome from the chaff of morbid relations. It is evident 

 that the same reasoning will again prove helpful in dissipating 

 the doubts so widely and keenly felt regarding the nature of our 

 connections with those invisible " parties " and their apparently 

 intangible influences, beneficial or detrimental, to which Butler 

 here refers. First of all, as Qualitative Biologists or Bio-Econo- 

 mists, we shall not fall into the error of applying the term 

 parasite at all in the case of organisms, be they never so small, 

 which contribute in a direct and vital manner to our own health 

 and to the common good of organic civilisation. We shall on the 

 contrary refer to them as symbiotic agents or Symbiotists 

 sharers in a wholesome Pan-Psychism. We shall discriminate 

 between organisms which, as scavengers, remove the offal of life, 

 rendering themselves indirectly useful, and between rank parasites 

 which lead a wholly non-reciprocal life, living merely destructively 

 on the substance of others sharers in a more or less morbid 

 Pan-Psychism. Not that we shall lay down any rules of con- 

 duct for organisms to obey ; but we shall point out the conse- 

 quences of every method of life, its value in organic civilisation, 

 and we shall discriminate accordingly. The directly useful 

 organisms, be it re-emphasised, flourish and survive in virtue of 

 their continuous usefulness and indispensability which guarantee 

 a super-adequacy of biological supports. Theirs is the method 

 of advance by the summation of powers, of Symbio-Psychism 

 as it were. The survival of scavengers and parasites, on the 

 other hand, is supported only by inferior connections, giving 

 them diminished powers of resistance to disease and lessened 

 survival capacity. Owing to the frailty of life, such organisms 

 as these ever recruit themselves from the ranks of the true 



