SOCIOLOGICAL METHODOLOGY 49 
that a law that prevails, or is thought to prevail, in biological 
evolution, prevails in like manner in the evolution of a social 
group or civilization taken as a whole. The fact would seem to 
be rather that each phase of development has its characteristic 
marks and can be understood only in the light of an inductive 
study of the elements that make up its own life. Moreover, while 
a knowledge of higher phases of development can be applied with 
a good degree of certainty to lower phases, the reverse is true 
only within limits which need to be carefully defined. 
GUILLAUME DE GREEF (1842- _—s=) 
Classification as a Method of Sociological Knowledge 
De Greef accepts Comte’s hierarchy of the sciences, but greatly 
extends it to include the social sciences.1_ In addition to Spencer’s 
principle of classification, — increasing complexity and de- 
pendence of parts, —he adds that of volitional activity or 
contractualism, which he holds to be “ the distinguishing char- 
acteristic of society, both from the structural and the functional 
point of view,” and defines as “‘ their superior and special mode of 
adaptation and life.” 2 
De Greef arranges the social elements in a hierarchy based on 
decreasing generality beginning with the economic and including 
in order, the industrial, genetic, artistic, scientific, moral, juridi- 
cal, and political. Not only does this scale stand for the order of 
generality, but also represents their related order of influence on 
social progress and on each other. ‘That is, the economic factor 
has great influence on social progress as a whole and on the politi- 
cal factor in particular, whereas the political factor has little 
influence on social progress and little on economic conditions.* 
1 Am. Journ. Soc., vii; Introduction a la Sociologie, Preface. 
2 Am. Journ. Soc., viii, p. 497. Cf. Barth, of. cit., p. 69. 
3 This is a good example of the artificialities into which some are led. Sucha 
harmonious cross-classification does not represent concrete life conditions. The 
fact is that government has more influence on the economic factor than it has 
on the religious, moral, or juridical, and, in fact, as Sumner has poiuted out, the 
moral is most often changed by legislation that has aimed to bring about certain 
industrial changes. Cf. Barth, zbid., p. 81; Small, General Sociology, pp. 68 ff. 
