| Having by these divisions given an order and arrangement to our objects, we may now apply ourselves to consider with the more accuracy their qualities and relations. |
| The first circumstance, that strikes my eye, is the great resemblance betwixt our impressions and ideas in every other particular, except their degree of force and vivacity. |
| The one seem to be in a manner the reflexion of the other; so that all the perceptions of the mind are double, and appear both as impressions and ideas. |
| When I shut my eyes and think of my chamber, the ideas I form are exact representations of the impressions I felt; nor is there any circumstance of the one, which is not to be found in the other. |
| In running over my other perceptions, I find still the same resemblance and representation. |
| Ideas and impressions appear always to correspond to each other. |
| This circumstance seems to me remarkable, and engages my attention for a moment. |
| Upon a more accurate survey I find I have been carried away too far by the first appearance, and that I must make use of the distinction of perceptions into simple and complex, to limit this general decision, that all our ideas and impressions are resembling. |
| I observe, that many of our complex ideas never had impressions, that corresponded to them, and that many of our complex impressions never are exactly copied in ideas. |
| I can imagine to myself such a city as the New Jerusalem, whose pavement is gold and walls are rubies, though I never saw any such. |
| I have seen Paris; but shall I affirm I can form such an idea of that city, as will perfectly represent all its streets and houses in their real and just proportions? |
| I perceive, therefore, that though there is in general a great, resemblance betwixt our complex impressions and ideas, yet the rule is not universally true, that they are exact copies of each other. |
| We may next consider how the case stands with our simple, perceptions. |
| After the most accurate examination, of which I am capable, I venture to affirm, that the rule here holds without any exception, and that every simple idea has a simple impression, which resembles it, and every simple impression a correspondent idea. |
| That idea of red, which we form in the dark, and that impression which strikes our eyes in sun-shine, differ only in degree, not in nature. |
| That the case is the same with all our simple impressions and ideas, it is impossible to prove by a particular enumeration of them. |
| Every one may satisfy himself in this point by running over as many as he pleases. |
| But if any one should deny this universal resemblance, I know no way of convincing him, but by desiring him to shew a simple impression, that has not a correspondent idea, or a simple idea, that has not a correspondent impression. |
| If he does not answer this challenge, as it is certain he cannot, we may from his silence and our own observation establish our conclusion. |
| Thus we find, that all simple ideas and impressions resemble each other; and as the complex are formed from them, we may affirm in general, that these two species of perception are exactly correspondent. |
| Having discovered this relation, which requires no farther examination, I am curious to find some other of their qualities. |