380 



ON THE HYPOTHESIS 



How far this petition was attended to, and the prostrate suppliant was ena 

 bled to obtain his object, we shall now proceed to examine. 



It is not necessary again to inquire whether the abstruse ideas of extension, 

 figure, and motion, time and space, together with various others of the same 

 kind, can or cannot be derived from mental reflection or external aens^ation. 

 I have already touched upon the subject, and must refer such of my audience 

 as are desirous of entering into it more deeply to the writings of Locke and 

 Tucker on the one side, and of Reid and Stewart on the other. I shall only 

 observe, in addition, that Mr. Stewart himself admits, with that liberality 

 which peculiarly characterizes his pen, that the ideas or notions of extension 

 and figure, which he somewhat quaintly denominates " the mathematical affec- 

 tions of matter," presuppose the exercise of our external senses.* But this 

 being admitted, they ought, if not derived from their immediate action, to be 

 fundamentally dependent upon them. 



Let us step forward at once to an investigation of the newly-discovered 

 and sublime principle itself, by which all these profundities are to be fathomed, 

 and ail the aberrations of sense and reason to be corrected. 



Many of my hearers will perhaps smile at the idea that this high and mighty 

 principle is nothing more than common sense ; but, in truth, the founder and 

 supporters of the northern system seem to have been wofully at a loss, not 

 only what name to give it, but what nature to bestow upon it ; and have hence 

 variously, and at times most cloudily and incongruously, described it, and 

 loaded it with as many names and titles as belong to a Spanish grandee or a 

 Persian prime minister. 



" If," says Dr. Reid, " there are certain principles, as I think there are, which 

 the constitution of our nature leads us to believe, and which we are under a 

 necessity to take for granted in the common concerns of life, without being able to 

 give a reason for them, these are what we call the principles of common sense."! 



Upon this passage I shall only, for the present, remark, that the new per- 

 cipient faculty, which it is the object of the Scottish theory to discover to us, 

 is one, as we have just been told, that is capable of extending its survey far 

 beyond " the common concerns of life," and of forming ideas of the mathe- 

 matical affections of matter ; and, consequently, that if the principles of com- 

 mon sense be limited, as they seem to be here, and in my judgment correctly 

 so, to " the common concerns of life," they can never answer the purpose to 

 which this faculty aspires, and for which it is started in the present hypothesis ; 

 which demands not only a common sense, but a moral and a mathematical 

 sense ; and all essentially distinct from, and totally independent of, corporeal 

 sensation and mental intelligence. 



It is much to be regretted, however, and forms an insuperable objection to 

 the whole hypothesis, that its founders have never been able to agree among 

 themselves upon the nature of their new principle. 



"The power or faculty," says Dr. Reid, "by which we acquire these con- 

 ceptions (those of extension, motion, and the other attributes of matter), must 

 be something different from any power of the human mind that hath been ex- 

 plained, since it is neither sensation nor re/lection.''''l 



This is loosely written; for it seems to intimate that there may be concep- 

 tions or ideas in the mind, derived from or dependent on itself, which are not 

 conceptions or ideas of reflection : while the phrase ideas of reflection, as em- 

 ployed in Locke's system, embraces ideas of every kind of which the mind is 

 or can be conscious, and which issue from any powers of its own. 



Dugald Stewart gives the same doctrine more correctly, as follows, and as 

 a paraphrase upon this very passage: " That w^e have notions of external 

 qualities which have no resemblance to our sensations, or to any thing of which 

 the mind is conscious, is therefore a fact of which every man's experience 

 affords the completest evidence, and to which it is not possible to oppose a 

 single objection, but its incompatibility with the common philosophical theo- 

 ries concerr^ing the origin of our knowledge. 



• Essays, vol. i. p. 95. t Inquiry, p. 52. t Reid, ch. v. sect. vii. Essays, vol. i. p. 549. 



i 



