5. But now for other Objections, That a Blind man would be able to discourse of Colours, if there were any Innate ideas in his Soul, I say, it does not at all follow; because these Ideas that I contend to be in the Soul, are not Sensible, but Intellectual, such as are those many Logical, Metaphysical, Mathematical, and some Moral Notions. All which we imploy as our own Modes of considering sensible Objects, but are not the sensible Objects themselves, of which we have no Idea, but onely a capacity, by reason of the Organs of our Body, to be affected by them. The reason therefore of a blind man's inability of discoursing of Colours, is onely that he has no Substratum or Phantasm of the Subject of the discourse, upon which he would use these innate Modes or frame of Notions that are naturally in his Mind, and which he can make use of in the speculation of sundry other sensible Objects.
See Book I. ch. 6. sect. 3.6. And whereas it is further Objected, That these Logical and Mathematical Notions came in also at the Senses, because Brutes have the knowledge of them, upon whom we will not bestow so rich an inward furniture as these Innate Ideas; I answer, that Brutes have not the knowledge of any such Notion, but what they act is from a mere Concatenation of sensible Phantasms representing things grateful or ungrateful to the Sense: as to instance in those particulars that are objected, That a Dog will bark at one noise, suppose the knocking at the door, and not at another, as the falling of a stool or of a dish from off a shelf; that he will follow one sent, as that of the Hare, and neglect another, and the like; these are all done, not that he has any Notion of Effect and Cause, but by mere Concatenation of Phantasms representing things as gratefull or ungratefull, or neither gratefull nor ungratefull to his Sense, in which case he is not mov'd at all. And if a Dog chop at the bigger morsel, it is not that he considers the notion of inequality; but because that sensible Object does more powerfully move his appetite. So if he take one single side of a Triangle to come to the corner of it, where a piece of bread may be placed, it is not because he considers that a straight line is the shortest betwixt the same terms, but he sensibly feels that going directly to it he shall be sooner at it then if he went about: as Zeno instances well in an Ass one corner of a Pasture & the fodder in the other, that he would goe directly to that corner the fodder lay in; which as he thought was a marvellous witty jeer to Euclide his Demonstration, that any two sides of a Triangle are bigger then the third, as being so plain a Truth that no Ass could miss of it.
7. But by the favour of so Critical a Philosopher, we may very well suspect that neither Dog nor Ass, that makes toward any Object, goes directly in a straight line to it because he considers that a crooked one is further about, but because the visual line guides him straight to the Object he looks at, in which he goes as naturally, without any reflexion upon Mathematical notions, as a stone cast out of a sling of it self endeavours to steer its course with a Motion rectilinear; which having not so much as Sense, we can in no wise suspect to be capable of the rudest Notion in Geometry.
8. Wherefore it is a mere fallacy, to argue that Brutes, because they doe such things as are reasonable or Mathematical, therefore they doe
