confefs that Vision is not made in a Point, when 'tis plain, that looking with one Eye there is always one part between the extreams of the Area that we fee, which is not feen at the fame time that we perceive the extreams of it, though the looking with two Eyes, or the quick turning of the Axis of the Eye to the part we would diftinctly view, when we look but with one, does not let us take notice of it,

10. What I have here faid I think fufficient to make intelligible, how by material Rays of Light vifible Species may be brought into the Eye, notwithftanding any of P.M.'s Objections, againft fo much of material Caufes, as my Hypothefis is concern'd in, But when by this means an Image is made pn the Retina, how we fee it, I conceive no more than when I am told we fee it in God, How we fee it, is I confefs, what I underderstand not in the one or in the other, only it appears to me more difficult to conceive a diftinct vifible Image in the uniform unvariable Effence of God, than in varioufly modi fiable Matter; but the manner how I fee either, ftill 'fcapes my Comprehenfion. Impreffions made on the Retina by Rays of Light, I think I understand; and motions from thence continued to the Brain may be conceived, and that thefe produce Ideas in our Minds, I am perfuaded, but in a manner

to

to me incomprehenfible. This I can refolve only into the good pleasure of God, whose ways are past finding out. And, I think, I know it as well when I am told thefe are Ideas that the motion of the Animal Spirits, by a Law establish'd by God, produces in me, as when I am told they are Ideas I fee in God. The Ideas 'tis certain I have, and God both ways is the original Caufe of my having them; but the manner how I come by them, how it is that I perceive, I confefs I understand not; though it be plain Motion has to do in the producing of them: And Motion fo modified, is appointed to be the cause of our having of them; as appears by the curious and artificial Structure of the Eye accommodated to all the Rules of Refraction and Dioptricks, that fo vifible Objects might be exactly and regularly painted on the bottom of the Eye.

II. The change of bignefs in the Ideas of vifible Objects, by Distance and OptickGlaffes, which is the next Argument he uses against visible Species, is a good Argu ment against them, as fuppos'd by the Peripateticks, but when confider'd, would perfuade one that we see the Figures and Magnitudes of things rather in the bottom of our Eyes than in God; the Idea we have of them and their Grandeur being still proportion'd to the bignefs of the Area, on L 4 the

the bottom of our Eyes, that is affected by the Rays which paint the Image there, and we may be faid to fee the Picture in the Retina, as when it is prick'd, we are truly faid to feel the pain in our Finger.

12. In the next place where he fays, that when we look on a Cube we fee all its fides equal. This, I think, is a mistake; and I have in another place fhewn, how the Idea we have from a regular Solid, is not the true Idea of that Solid, but fuch an one as by Custom (as the name of it does,) serves to excite our Judgment to form fuch

an one.

13. What he fays of feeing an Object feveral millions of Leagues, the very fame instant that it is uncover'd, I think may be fhewn to be a mistake in matter of fact, For by Obfervations made on the Satellites of Jupiter, it is difcover'd that Light is fucceflively propagated, and is about ten Minutes coming from the Sun to us.

14. By what I have faid I think it may be understood how we may conceive, that from remote Objects material Caufes may reach our Senfes, and therein produce feveral motions that may be the caufes of Ideas in us; notwithstanding what P.M. has faid in this fecond Chapter against material Species. I confefs his Arguments are good against thofe Species as ufually un

derstood

derstood by the Peripateticks. But fince my Principles have been faid to be conformable to the Ariftotelian Philofophy, I have endeavour'd to remove the difficulties it is charged with as far as myOpinion is concern'd in them.

15. His third Chapter is to confute the Opinion of those who think our Minds have a power to produce the Ideas of things on which they would think, and that they are excited to produce them by the impreffions which Objects make on the Body. One who thinks Ideas are nothing but Perceptions of the Mind annexed to certain motions of the Body by the Will of God, who hath order'd fuch Perceptions always to accompany fuch motions, though we know not how they are produced, does in effect conceive those Ideas or Perceptions to be only Paffions of the Mind, when produced in it, whether we will or no, by external Objects. But he conceives them to be a mixture of Action and Paffion when the Mind attends to them or revives them in the Memory. Whether the Soul has fuch a Power as this, we fhall perhaps have occafion to confider hereafter; and this Power our Author does not deny, fince in this very Chapter he fays, When we conceive a Square by pure understanding, we can yet imagine it, i. e. perceive it in our felves by tracing an Image of it on the Brain Here

then

then he allows the Soul power to trace Images on the Brain, and perceive them. This, to me, is Matter of new perplexity in his Hypothefis; for if the Soul be fo united to the Brain as to trace Images on it, and perceive them, I do not fee how this confifts with what he fays a little before in the first Chapter, viz. That certainly material things cannot be united to our Souls after a manner neceffary to its perceiving them.

16. That which is faid about Objects exciting Ideas in us by motion; and our reviving the Ideas we have once got in our Memories, does not, I confefs, fully explain the manner how it is done. In this I frankly avow my Ignorance, and fhould be glad to find in him any thing that would clear it to me; but in his Explications I find thefe difficulties which I cannot get over,

17. The Mind cannot produce Ideas, fays he, because they are real Spiritual Beings, i. e. Substances; for fo the Conclu fion of that Pharagraph where he mentions it as an Abfurdity to think they are annihilated when they are not prefent to the Mind. And the whole force of this Argument would perfuade one to understand him fo; though I do not remember that he any where speaks it out, or in direct terms calls them Subftances,