36 INTRODUCTION. 



even among those who have studied the subject most carefully. But 

 these discrepancies have not prevented the introduction, nor destroyed 

 the utility, of a natural system in the former case ; nor can we see 

 any greater reason why they should produce these effects in the latter. 

 In either case, the study of these relations cannot fail to suggest new 

 ideas, and to prove a useful exercise for the mind. 



It may perhaps be objected, that some terms, applied to large divi- 

 sions of knowledge, and now in general use, have been omitted in the 

 nomenclature here proposed. The answer is, that these terms are 

 so vaguely or variously applied, as to be unsuitable for a more exact 

 division. Of the term Philosophy, we have already spoken, (p. 19, 

 20) ; and will only add that there is no one province, nor department 

 of knowledge, for which it would, in our view, be a definite, and pre- 

 cise appellation. We would rather apply it, in its original sense, to 

 knowledge, or the principles of knowledge in general. Knowledge 

 is often spoken of under the three divisions of Literature, Science, and 

 the arts. But Literature, as already mentioned, (p. 24), more pro- 

 perly signifies written and printed knowledge of every kind : or if 

 applied in a more limited sense, to designate those studies which relate 

 to man in his social and moral relations, the term is still indefinite. 

 Equally indistinct is the division between Sciences, and Arts. Science 

 is the theory, and <flrt is the application of that theory to some prac- 

 tical purpose. Science explains principles, and Art describes pro- 

 cesses ; but these are often so essentially connected, that to separate 

 them would be an unnatural divorce. Thus, the Physical Sciences 

 employ processes which might almost rank them as arts ; and the 

 Physical Arts have their own peculiar principles, which might almost 

 entitle them to be ranked as sciences. Grammar is both a science, 

 and an art ; and the same may be said of Rhetoric, Logic, and other 

 branches; but still they are single and distinct branches of knowledge. 



There are two other terms, which should here be particularly 

 referred to; Metaphysics, and Belles Lettres. The name Metaphy- 

 sics, originated in a treatise by Aristotle, which, coming after his 

 writings on Physics, began with the words ^ra <pvoi K a, that is, after 

 physics; and which speculated vaguely on subjects beyond the reach 

 of exact knowledge. Hence the term Metaphysics was coined by his 

 pupils, or by the schoolmen, to signify " the science of the ultimate 

 causes of all being." It has been divided into Ontology, relating to 

 the nature and essence of all being or existence, with its qualities and 

 attributes ; Cosmology, or the nature of the material world, including 

 the question of Leibnitz, whether God must necessarily have created 

 it perfect, and whether it is so in fact; Anthropology, or the nature 

 and essence of man; Pneumatology, or that of unembodied spirits; 

 and Theodicy, which attempts to investigate the nature, essence, and 

 attributes of the Deity. To Metaphysics belong such wild specula- 

 tions as those of Pythagoras, already mentioned, (p. 20), and the later 

 hypothesis of Formey, " that sensation is carried on entirely by 

 means of vibrations, which are communicated through the nerves, 

 from the first point of contact, till they reach the farthest extremities, 

 which are dipped in a spiritual fluid" So much of Metaphysics, 

 then, as consists of real knowledge, or rational conjecture, will be 



