Essay Concerning Human Understanding
Essay Concerning Human Understanding

Essay Concerning Human Understanding

First, I shall inquire into the original of those ideas, notions, or whatever else you please to call them, which a man observes, and is conscious to himself he has in his mind; and the ways whereby the understanding comes to be furnished with them. (LocationĀ 744)

2. All ideas come from sensation or reflection. Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas; (LocationĀ 1275)

To this I answer, in one word, from experience: in that, all (LocationĀ 1278)

3. The objects of sensation one source of ideas. First, our senses, conversant about particular sensible objects, do convey into the mind, several distinct perceptions of things, according to those various ways, (LocationĀ 1281)

perception, thinking, doubting, believing, reasoning, knowing, willing, and all the different actings of our own minds; (LocationĀ 1290)

REFLECTION, the ideas it affords being such only, as the mind gets by reflecting on its own operations within itself. (LocationĀ 1294)

All our ideas are of the one or the other of these. The understanding seems to me, not to have the least glimmering of any ideas, which it does not receive from one of these two. External objects furnish the mind with the ideas of sensible qualities, (LocationĀ 1300)

The impressions then, that are made on our senses by outward objects, that are extrinsical to the mind, and its own operations, about the impressions, reflected on by itself, as proper objects to be contemplated by it, are, I conceive, the original of all knowledge; (LocationĀ 1389)

10. Simple ideas the materials of all our knowledge. These, if they are not all, are at least (as I think) the most considerable of those simple ideas which the mind has, and out of which is made all its other knowledge; (LocationĀ 1519)

9. Primary and secondary qualities. Qualities thus considered in bodies are, first such as are utterly inseparable from the body, (LocationĀ 1571)

and reasonings, has no other immediate object but its own ideas, which it alone does or can contemplate, it is evident, that our knowledge is only conversant about them. (LocationĀ 4990)

Knowledge then seems to me to be nothing but the perception of the connection and agreement, or disagreement and repugnancy of any of our ideas. (LocationĀ 4992)

For when we know that white is not black, what do we else but perceive, that these two ideas do not agree? When we possess ourselves with the utmost security of the demonstration, 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 necessarily agree to, and is inseparable from the three angles of a triangle? (LocationĀ 4994)

all, to perceive its ideas, and so far as it perceives them, to know each what it is, and thereby also to perceive their difference, and that one is not another. This is so absolutely necessary, that without it there could be no knowledge, no reasoning, no imagination, no distinct thoughts at all. (LocationĀ 5004)

Fourthly, the fourth and last sort is that of actual real existence agreeing to any idea. (LocationĀ 5026)

Thus blue is not yellow, is of identity. (LocationĀ 5030)

Two triangles upon equal basis, between two parallels are equal, is of relation. (LocationĀ 5031)

Iron is susceptible of magnetical impressions, is of coexistence, (LocationĀ 5031)

GOD is, is of real existence. (LocationĀ 5032)

There is actual knowledge, which is the present view the mind has of the agreement, or disagreement of any of its ideas, or of the relation they have one to another. (LocationĀ 5037)

it. This, I think, one may call habitual knowledge: and thus a man may be said to know all those truths, which are lodged in his memory, by a foregoing clear and full perception, whereof the mind is assured past doubt, as often as it has occasion to reflect on them. (LocationĀ 5042)

clearest, and most certain, that human frailty is capable of. (LocationĀ 5090)

The next degree of knowledge is, where the mind perceives the agreement or disagreement of any ideas, but not immediately. (LocationĀ 5099)

yet it does not always happen, that the mind sees that agreement or disagreement, which there is between them, even where it is discoverable; (LocationĀ 5101)

The reason why the mind cannot always perceive presently the agreement or disagreement of two ideas is, because those ideas, concerning whose agreement or disagreement the inquiry is made, cannot by the mind be so put together, as to show it. (LocationĀ 5102)

Thus the mind being willing to know the agreement or disagreement in bigness, between the three angles of a triangle, and two right ones, cannot by an immediate view and comparing them, do it: (LocationĀ 5107)

the three angles of a triangle cannot be brought at once, and be compared with any other one, or two angles; and so of this the mind has no immediate, no intuitive knowledge. In (LocationĀ 5108)

Those intervening ideas, which serve to show the agreement of any two others, are called proofs; (LocationĀ 5111)

though it be certain, yet the evidence of it is not altogether so clear and bright, nor the assent so ready, as in intuitive knowledge. (LocationĀ 5115)

There can be nothing more certain, than that the idea we receive from an external object is in our minds; this is intuitive knowledge. But whether there be anything more than barely that idea in our minds; whether we can thence certainly infer the existence of anything without us, which corresponds to that idea, is that, where of some men think there may be a question made, because men may have such ideas in their minds, when no such thing exists, no such object affects their senses. (LocationĀ 5178)

for I ask anyone, whether he be not invincibly conscious to himself of a different perception, when he looks on the sun by day, and thinks on it by night; when he actually tastes wormwood, or smells a rose, or only thinks on that savor, or odor? (LocationĀ 5182)