“All matter surely is, in itself, as it is,” said Metrodorus with a smile; “and that, I should say, is living and active. Again, what is matter?”
“All that is evident to our senses,” replied Theon, “and which stands opposed to mind.”
“All matter then is inert which is devoid of mind. What, then, do you understand by mind?”
“I conceive some error in my definition,” said Theon, smiling. “Should I say—thought—you would ask if every existence devoid of thought was inert, or if every existence, possessing life, possessed thought?”
“I should so have asked. Mind or thought I consider a quality of that matter constituting the existence we call a man, which quality we find in a varying degree in other existences; many, perhaps all animals, possessing it. Life is another quality, or combination of qualities, of matter, inherent in—we know not how many existences. We find it in vegetables; we might perceive it even in stones, could we watch their formation, growth, and decay. We may call that active principle, pervading the elements of all things, which approaches and separates the component particles of the ever changing, and yet ever during world—life. Until you discover some substance, which undergoes no change, you cannot speak of inert matter: it can only be so, at least, relatively,—that is, as compared with other substances.”
“The classing of thought and life among the qualities of matter is new to me.”
“What is in a substance cannot be separate from it. And is not all matter a compound of qualities? Hardness, extension, form, color, motion, rest—take away all these, and where is matter? To conceive of mind independent of matter, is as if we should conceive of color independent of a substance colored: What is form, if not a body of a particular shape? What is thought, if not something which thinks? Destroy the substance, and you destroy its properties; and so equally—destroy the properties, and you destroy the substance. To suppose the possibility of retaining the one, without the other, is an evident absurdity.”
“The error of conceiving a quality in the abstract often offended me in the Lyceum,” returned the youth, “but I never considered the error as extending to mind and life, any more than to vice and virtue.”
“You stopped short with many others,” said Leontium. “It is indeed surprising how many acute minds will apply a logical train of reasoning in one case, and invert the process in another exactly similar.”
“To return, and, if you will, to conclude our discussion,” said Metrodorus, “I will observe that no real advances can be made in the philosophy of mind, without a deep scrutiny into the operations of nature, or material existences. Mind being only a quality of matter, the study we call the philosophy of mind, is necessarily only a branch of general physics, or the study of a particular part of the philosophy of matter.”