19 
which enables us to classify these objects. And we must 
observe that even in this very first step in Science, in which 
law means nothing more than the order of contemporaneous 
existences, unity must be assumed, before we can assure our- 
selves that Science is possible. For without unity all know- 
ledge is fragmentary, and order, which is the expression of the 
relations of the different existences to one another and to the 
whole, could never be investigated. The order also, which is 
required to be available for scientific knowledge, must be 
fixed and determinate in such a sense that its variations will 
be according to order, and not irregular or promiscuous. 
But it is important to observe what is implied in the order 
which Science recognises in the universe. It involves the idea 
implied in the Greek word kog/ioq, that is, the suitable 
arrangement and adaptation of the different parts of the whole. 
Without discussing the somewhat difficult question of scientific 
classification, it is sufficient to say that the order demanded 
by Science implies a whole so divided and subdivided, with 
relations between the several parts, that in a complete 
scientific scheme the exact position of any particular 
object may be determined with certainty ; and any such 
scheme is truly scientific in proportion as the order is not 
artificial and technical, but conformable with that which Nature 
itself indicates. For it must be observed that the order of 
Nature does not consist of a series of existences differing from 
one another by imperceptible degrees. Such a universe is quite 
conceivable, but in it Science would have no place, because 
natural classification would be impossible. In the universe as it 
is, while the number of those existences, the differences between 
which are accidental to the individual, is indefinite, yet the 
number of different classes of such identities is finite, and the 
differences between these classes, instead of being infinitesimal, 
are sufficient distinctly to separate one class from another. 
To apply the terms of Evolution to the contemporaneous order 
of Nature, Science proceeds on the assumption that there is a 
limited number of integrations in Nature; and the office of 
Science is to determine these integrations with exactness. For 
example, while the material constituents of this earth and its 
surroundings are readily recognised even by the senses as 
different from one another ; yet this order, as observed unscien- 
tifically, is more or less confused. It belongs to Science to 
classify them as distinct integrations, and to exhibit each of 
them as possessing its distinctive character and properties. 
Chemistry, which investigates the composition of these several 
constituents, throws further light on the order in the unity of 
the visible universe, by proving that everything material is 
c 2 
