5. Secondly, Want of Skill to use them. 6. Thirdly, Want of Will to use them. 7. Fourthly, Wrong Meafures of Probability, whereof) 8-10. Firft, Doubtful Propofitions taken for Principles. 11. Secondly, Received Hypothefes. 12. Thirdly, Predominant Paffions. 13. The Means of evading Probabilities, 1, Suppofed 14. 2dly, Suppofed Arguments for the contrary. 15. What Probabilities determine the Affent. OF HUMAN UNDERSTANDING. BOOK IV.-CHAP. I. OF KNOWLEDGE IN GENERAL. §1. Our Knowledge converfant about our Ideas. INCE the mind, in all its thoughts and reafon ings, hath no other immediate object but its own ideas, which it alone does or can contemplate, it is evident, that our knowledge is only converfant about them. § 2. Knowledge is the Perception of the Agreement or Difagreement of two Ideas. KNOWLEDGE then feems to me to be nothing but the perception of the connection and agreement, or disagreement and repugnancy of any of our Ideas. In this alone it confifts. Where this perception is, there is knowledge; and where it is not, there, though we may fancy, guess, or believe, yet we always come short of knowledge. For when we know that white is not black, what do we elfe but perceive that these two ideas do not agree? when we poffefs ourselves with the utmost fecurity of the demonftration, that the three angles of a triangle are equal to two right ones, what do we more but perceive, that equality to two right. ones, does neceffarily agree to, and is infeparable from the three angles of a triangle? $3. This Agreement fourfold. Bur to understand a little more diftinctly, wherein this agreement or disagreement confifts, I think we may reduce it all to these four forts: 1. Identity, or diverfity. 3. Co-existence, or neceffary connectiɔn. $4. 1. Of Identity or Diverfity. FIRST, As to the first fort of agreement or difagreement, viz. identity or diverfity, It is the firft act of the mind, when it has any fentiments or ideas at all, to perceive its ideas; and fo far as it perceives them, to know each what it is, and thereby alfo to perceive their difference, and that one is not another. This is fo abfolutely neceffary, that without it there could be no knowledge, no reasoning, no imagination, no diftinct thoughts at all. By this the mind clearly and infallibly perceives each idea to agree with itself, and to be what it is; and all distinct ideas to difagree, i. e. the one not to be the other: and this it does without pains, labour or deduction, but at first view, by its natural power of perception and diftinction. And though men of art have reduced this into thofe general rules, What is, is; and it is impoffible for the fame thing to be, and not to be; for ready application in all cafes, wherein there may be occafion to reflect on it; yet it is certain, that the firft exercise of this faculty is about particular ideas. A man infallibly knows, as foon as ever he has them in his mind, that the ideas he calls white and round, are the very ideas they are, and that they are not other ideas which he calls red or fquare: Nor can any maxim or propofition in the world make him know it clearer or furer than he did before, and without any fuch general role. This then is the firft agreement or disagreement, which the mind perceives in its ideas; which it always perceives at first fight: and if there ever happen any doubt about it, it will always be found to be about the names, and not the ideas themfelves, whofe identity and diverfity will always be perceived, as foon and as clearly as the ideas themfelves are, nor can it poffibly be otherwife, $5. 2. Relative. SECONDLY, The next fort of agreement, or difagreement, the mind perceives in any of its ideas, may, I think, be called relative, and is nothing but the perception of the relation between any two ideas, of what kind foever, whether fubftances, modes, or any other. For fince all distinct ideas must eternally be known not to be the fame, and fo be univerfally and constantly denied one of another, there could be no room for any pofitive knowledge at all, if we could not perceive any relation between our ideas, and find out the agreement or difagreement they have one with another, in feveral ways the mind takes of comparing them. $6. 3. Of Co-existence. THIRDLY, The third fort of agreement, or difagreement, to be found in our ideas, which the perception of the mind is employed about, is co-existence, or nonco-exilence in the fame fubject; and this belongs particularly to fubitances. Thus, when we pronounce concerning gold that it is fixed, our knowledge of this truth amounts to no more but this, that fixedness, or a power to remain in the fire unconfumed, is an idea that always accompanies and is joined with that particular fort of yellowness, weight, fufibility, malleablenefs, and folubility in aqua regia, which make our complex idea, fignified by the word gold. $7. 4. Of real Exiftence. FOURTHLY, The fourth and lait fort is that of actual real exiftence agreeing to any idea. Within thefe four forts. of agreement or difagreement, is, I fuppofe, contained. all the knowledge we have, or are capable of: For all the inquiries that we can make concerning any of our ideas, all that we know or can affirm concerning any of them, is, that it is, or is not, the fame with fome other; that it does, or does not, always co-exift with fome other idea in the same subject; that it has this or that relation to fome other idea; or that it has a real exiftence without the mind. Thus blue is not yellow, is of identity: Two triangles upon equal bafes between two parallels are equal, is of relation: Iron is fufceptible of magnetical impreffions is of co-existence: God is, is of real exiftence. Though identity and co-exiftence are truly nothing but relations, yet they are fo peculiar ways of agreement or difagreement of our ideas, that they deferve well to be confidered as diftin& heads, and not under relation in general; fince they are fo different grounds of affirmation and negation, as will eafily appear to any one, who will but reflect on what is faid in feveral places of this effay. I should now proceed to examine the feveral degrees of our knowledge, but that it is neceffary firft to confider the different acceptations of the word knowledge. § 8. Knowledge actual or habitual. THERE are several ways wherein the mind is poffeffed of truth, each of which is called knowledge. 1. There is actual knowledge, which is the prefent view the mind has of the agreement or difagreement of any of its ideas, or of the relation they have one to another. : 2. A man is faid to know any propofition, which having been once laid before his thoughts, he evidently perceived the agreement or difagreement of the ideas whereof it confifts; and fo lodged it in his memory, that whenever that propofition comes again to be reflected on, he, without doubt or hefitation, embraces the right fide, affents to, and is certain of the truth of it. This, I think, one may call habitual knowledge and thus a man may be faid to know all thofe truths which are lodged in his memory, by a foregoing clear and full perception, whereof the mind is affured past doubt, as often as it has occafion to reflect on them. For our finite understandings being able to think clearly and diflinctly but on one thing at once, if men had no knowledge of any more than what they actually thought on, they would all be very ignorant; and he that knew moft would know but one truth, that being all he was able to think on at one time. |