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Proceedings of the Royal Society 
systems, bearing sometimes geographical names, as British school, 
Italian school, sometimes named after their founders, or sometimes 
designated by some prominent aspect of their doctrine, as Socialism, 
Communism, &c., each claiming orthodoxy and opposing its con- 
temporaries obliquely or diametrically. This state of things, 
fortunately unique in science, makes desirable an exhaustive 
study and classification of all these rival systems ; but within 
our present limits it is only possible to attempt a brief glance 
at their main points of difference and of agreement. 
hirst, then, they differ as to whether the subject be a science at 
all, some authors regarding it as an art, others as something 
distinct from both. Kestricting ourselves henceforth to the great 
majority of schools which hold the first-mentioned opinion, we find 
them agree in the extensive adulteration of their scientific matter 
with irrelevant discussions, which are occasionally of a theological 
nature, but much oftener metaphysical, and most frequently practical 
— a peculiarity which helps to explain the low esteem into which the 
subject has been steadily falling during the last generation, among 
theologians and metaphysicians, practical and scientific men alike. 
Such digressions are, however, common to the infancy of every 
department of knowledge, and must not, therefore, be too hardly 
dwelt upon. A more serious difficulty lies in the want of unanimity 
among the various schools as to the position of their subject with 
respect to other sciences, some spending no little labour in an 
endeavour to isolate it from other branches of knowledge altogether, 
while others claim it to be a logical science, others a mathematical, 
others a physical, others a biological, others a psychological, 
others a sociological, others an ethical science, while some 
hold it to belong partly to one and partly to another. In 
other words, the subject has been referred to every possible 
position in the classification of the sciences with the ex- 
ceptions of astronomy, chemistry, and geology. And while it 
must be admitted that the teachers of these various systems are 
usually admirable as logicians, and that many also freely use 
mathematical reasonings and illustrations, they do not apply their 
knowledge to any great extent in the quantitative study of pheno- 
mena nor to the analysis of the facts recorded by statisticians. And 
again, although political economy is said to deal largely with material 
