ON MATERIALISM AND 1MMATERIALISM. 323 



As a part of physics, or natural philosophy, it was uniformly arranged by the 

 Greeks ; as such it occurs in the works of Aristotle, as such it was regarded 

 by Lord Bacon, as such we meet with it in Mr. Locke's correct and compre- 

 hensive classification of science, and as such it has been generally treated of 

 by the Scottish professors of our own day. And I may add that it is very 

 much in consequence of so unnatural a divorce, that the science of metaphy- 

 sics has too often licentiously allied itself to imagination, and brought forth a 

 monstrous and chimerical progeny. 



The term, though a Greek compound, is not to be found among the Greek 

 writers. The first traces of it occur to us in the Physics of Aristotle, the last 

 fourteen books of which are entitled in the printed editions, Tfiv/rdr<2 *<*: 

 ** Of Things relating to Physics ;" but even this title is generally supposed to 

 have been applied, not by Aristotle himself, but by one of his commentators, 

 probably Andronicus, on the transfer of the manuscripts of Aristotle to Rome, 

 upon the subjugation of Asia by Syll'a, in which city this invaluable treasure, 

 as we had occasion to observe not long ago, had been deposited as part of the 

 plunder of the library of Apellicon of Teia.* 



In taking a general survey of the subject immediately before us, there are 

 three questions that have chiefly occupied the attention of the world ; the 

 essence of the mind or soul ; its durability ; and the means by which it main- 

 tains a relation with the sensible or external world. Let us devote the pre- 

 sent lecture to a consideration of the first of these. 



Is the essence of the human soul material or immaterial 1 The question, 

 at first sight, appears to be highly important, and to involve nothing less than 

 a belief or disbelief, not indeed in its divine origin, but in its divine similitude 

 and immortality. Yet I may venture to affirm that there is no question which 

 has been productive of so little satisfaction, or has laid a foundation for wider 

 and wilder errors, within the whole range of metaphysics. And for this 

 plain and obvious reason, that we have no distinct idea of the terms, and no 

 settled premises to build upon.f Corruptibility and incorruptibility, intelli- 

 gent and unintelligent, organized and inorganic, are terms that convey distinct 

 meanings to the mind, and impart modes of being that are within the scope 

 of our comprehension: but materiality and immateriality are equally beyond 

 our reach. Of the essence of matter we know nothing; and altogether as 

 little of many of its more active qualities ; insomuch that, amid all the disco- 

 veries of the day, it still remains a controvertible position whether light, heat, 

 magnetism, and electricity are material substances, material properties, or 

 things superadded to matter and of a higher rank. If they be matter, gra- 

 vity and ponderability are not essential properties of matter, though com- 

 monly so regarded. And if they be things superadded to matter, they are 

 necessarily immaterial ; and we cannot open our eyes without beholding innu- 

 merable instances of material and immaterial bodies coexisting and acting in 

 harmonious unison through the entire frame of nature. But if we know 

 nothing of the essence, and but little of the qualities, of matter, of that com- 

 mon substrate which is diffused around us in every direction, and constitutes 

 the whole of the visible world, what can we know of what is immaterial ? 

 of the Cull meaning of a term that, in its strictest sense, comprehends all the 

 rest of the immense fabric of actual and possible being, and includes in its 

 vast circumference every essence and mode of essence of every other being, 

 as well below as above the order of matter, and even that of the Deity 

 himself 1} 



Shall we take the quality of extension as the line of separation between 

 what is material and what is immaterial 1 This, indeed, is the general and 

 favourite distinction brought forward in the present day, but it is a distinction 

 founded on mere conjecture, and which will by no means stand the test of 

 inquiry. Is space extended? every one admits it to be so. But is space ma- 

 terial ? is it body of any kind? Des Cartes, indeed, contended that it is body, 

 and a material body, for he denied a vacuum, and asserted space to be a part 



* Series ir. Lecture xi. | See Locke on Hum. Underst. ch. xxiii. book ii. 



t Study of Med. vol. iv. p. 37, 2d edit. 



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