1. The Epistle to the Reader
The discussion that started it all
Limitations on human knowledge
Religious toleration
The project
Controversy
“Underlabourer” passage
Scientific progress
Rubbish
Abuse of language

2. Introduction The topic The plan Benefits ‘Ideas’
origin of ideas, how the understanding is furnished with them
knowledge, its certainty, evidence, extent
nature/grounds of faith/opinion, reasons/degrees of assent
Benefits
Caution
Against defeatism
Probability and certainty
Defeatism and skepticism
Wise investment of intellectual resources
‘Ideas’
Descartes and Locke
‘perception’ and ‘perceives’

3. Review of nativism
There is no innate knowledge of principles / maxims like “whatsoever is, is”.
After all, no such maxims are universally accepted.
Children, idiots, etc. don’t even understand them, much less accept them.
Various weakenings of ‘universal acceptance’ into some universal latent knowledge end up facing chronic problems.
Problems like: you might contradict yourself, or you might lose the distinction between innate and non-innate truths.
Such problems undermine popular ‘fallback’ versions of nativism (e.g., ‘use of reason’ and ‘immediate acceptance’).
This doesn’t just undermine a standard argument for nativism; it also provides an argument against nativism.
1.2

4. Review of nativism Innate ideas Important ideas fail to be innate
Propositions are made up of ideas.
So innate principles require innate ideas.
But, Locke thinks, the ideas found in maxims are not innate.
Children learn particular things before they learn universal abstract principles
They acquire the idea HUNGRY before the idea IMPOSSIBLE.
Important ideas fail to be innate
Identity? No, it’s too unclear and puzzling.
Whole/part? No, otherwise extension/number are innate.
God? No, too many atheists, polytheists, and silly images of God sitting on a cloud.
Substance? No, it’s far too unclear.
1.4

5. Review of nativism Nativism (innate principles, ideas)
There’s no good case for it.
There’s a good case against it.
There’s a good alternative explanation of human thought and knowledge.
It would be impertinent to think that God endowed us with innate knowledge and ideas, if we could get it all simply by using our innate faculties.
In Book 2, Locke begins giving his alternative explanation of human thought and knowledge.

6. All ideas taken from experience
Human minds contain ideas.
ideas are what the mind directly perceives
ideas are what words express
language-psychology connection
ideas are “the materials of Reason and Knowledge”
But how do minds end up with ideas?
not innately imprinted
One word: experience
experience doesn’t directly provide knowledge
it provides ideas: the materials of knowledge
2.1

7. Sensation and reflection
Two kinds of experience
sensation [external]
reflection [internal]
Sensation
The senses deal with particular sensible objects, with sensible qualities
This produces certain perceptions in the mind
Namely, ideas of sensible qualities
e.g., yellow, white, heat, cold, soft, hard, bitter, sweet

8. Sensation and reflection
I introspectively perceive my own mental operations (i.e., I’m aware of my mind operating on ideas)
This produces other ideas: ideas of mental operations
e.g., perception, thinking, doubting, believing, reasoning, knowing, willing
‘Operations’ here includes not just mental actions on ideas, but passions/feelings arising from ideas

9. Sensation and reflection
All ideas are ultimately* taken from experience, be it sensation or reflection.
“We have nothing in our Minds, which did not come in, one of these two ways”
*[Some ideas are not directly taken from experience; but they come from other ideas that are directly taken from experience]
Examine your own ideas: are there any that were not ultimately taken from experience?

10. Acquisition of ideas Children Paying close attention
They start out without many ideas, and they gradually acquire them (and some ideas don’t show up until very late)
By controlling a child’s surroundings, you could control the ideas she acquires.
If you kept her in a black-and-white environment, she would never have ideas of colors.
Paying close attention
People get different ideas depending on their surroundings as well as the attention they pay.
Ideas of reflection come later and are seldom very clear because they require close attention.
The external world often distracts children and even adults from the operations of their own mind.

11. Is the soul always thinking?
Descartes would say that ideas come in along with the soul.
The soul is essentially a thinking thing.
The soul cannot exist without thinking.
Thinking = perceiving ideas.
Hence where there’s a soul, there must be ideas.
But Locke doubts that the soul is always thinking.
Sometimes there is dreamless sleep (we are not aware of any thinking, and thinking requires awareness).
Thinking isn’t the essence of the soul, it’s just one of its operations.
[FYI: Against Descartes, Locke accepts nonthinking souls (dreamless sleep) and immaterial extension (empty space).]

12. Unconscious thinking?
Does dreamless sleep involve unconscious thinking?
Suppose this thinking involves happiness or misery.
Unconscious happiness/misery seems impossible.
Unconscious happiness/misery would make the sleeping person from the awake person into two different persons.
The awake person would be unaware of and hence unconcerned with the happiness/misery of the sleeping person.
And if P1 = P2, then P1 must at least be aware of and concerned for P2’s happiness/misery.

13. Forgotten conscious thinking?
Does dreamless sleep involve conscious thinking that we have no memory of?
Again, personal identity is threatened.
Suppose there is one soul shared between two bodies, Castor and Pollux, who sleep and wake by turns.
Whenever Castor falls asleep, his soul goes into Pollux, who then wakes up. And when Pollux falls asleep, the soul returns to Castor, who then wakes up.
Since Castor has no memory of Pollux’s mental life, and vice versa, they are two different persons.
So we have a single soul and two different persons; hence neither person is identical with his soul.
[FYI: This discussion of personal identity anticipates Locke’s classic discussion in 2.27, which appeals to a continuity of consciousness/awareness]

14. Is the soul always thinking?
Other points
Thinking while asleep and never remembering it is perfectly useless.
Sleeping thoughts ought to be more rational, because separated from the body; yet dreams are crazy.
If the soul has ideas not based in experience, then those ideas should sometimes show up in this sleeping thought, and yet we never remember any such ideas.
How could Descartes come to know that he always thinks?
How could he know that other people always think, especially when they themselves aren’t aware of it? By magic?

15. Acquisition of ideas, again
Children
Newborns spend most of their time asleep, “without Perception or Thought”
As the child gains ideas, it spends more time thinking and awake.
And it gains skill at different kinds of thinking.
Ideas don’t show up until the senses are active; and only then can mental operations begin.
Conclusion
Sensation and reflection are the basis of knowledge.
The mind has an innate capacity to receive impressions made on it by sensation and reflection.
In the receiving of ideas, the understanding is passive (at least “for the most part”)—we can’t will this process to stop.

16. Lockean empiricism Passive/limited: Active/powerful:
The mind is (mostly) passive at receiving ideas.
Our thought is constrained by the limited material provided by experience.
Active/powerful:
But the mind is active at tinkering with ideas: we have the power to abstract, compare, combine, and enlarge.
Our mind has powerful processing machinery available.

17. Lockean empiricism Positive side:
Using our natural faculties on the limited materials taken from experience, we can arrive at very complicated and sophisticated ideas.
Alphabet/words example, number/mathematics example (2.7.10)
We can even arrive at self-evident knowledge of basic maxims (the sorts of statements rationalists take to be innate).
Negative side:
There are some ideas we are alleged to have, which we do not in fact have.
We have no positive idea of infinity, our idea of substance in general is very unclear, we cannot know the real essence of mind or of matter, etc.

18. Simple ideas Getting simple ideas Experiential uniformity
We observing many qualities united together in a single object.
But we receive the distinct ideas of those qualities separately, as simple ideas.
Experiential uniformity
A simple idea “contains in it nothing but one uniform Appearance, or conception in the mind”
It “is not distinguishable into different Ideas”
[Later (3.4.4), Locke says that “[t]he Names of simple Ideas are not capable of any definitions”; after all, you can’t break these ideas down into simpler parts]
2.2.1

19. Simple ideas
Simple ideas are taken directly from sensation and reflection.
Power over simple ideas
We can tinker with simple ideas and make new complex ideas
We have “the power to repeat, compare, and unite [simple ideas]”
But we cannot make up new simple ideas, nor destroy the ones we have.
Try to think up or imagine a new color or taste.
2.2.2,3

20. Different kinds of simple ideas
[Probably not terribly important]
One-sense: Some simple ideas are received through one sense only (smell, color, solidity)
Very few of these simple ideas have names.
Many-senses: Some through different senses (extension, shape, motion).
Reflection: Some through reflection (perception/thinking, volition/willing)
Reflection-and-sensation: Some through both (pain/pleasure, existence, unity, power, succession)

21. Idea of solidity
Received from the sense of touch when one body resists another.
Space:
The idea of solidity leads us to imagine a body filling up space so as to exclude other bodies.
But the idea of solidity is distinct from the idea of space: we can have the idea of a body moving (space) without any other bodies being affected (solidity).
Space comprises “unsolid, inseparable, and immoveable Parts”.
Hardness:
The idea of solidity is also distinct from the idea of hardness.
Even air or water can exhibit solidity/resistance.

22. The “veil of perception”
Locke on sense perception of external objects:
[This view is commonly ascribed to Locke]
You directly ‘see’ an idea.
The idea has been caused by, and represents (by resembling), an external object.
In this way, you indirectly see the object.
Objections:
To see objects, you need an intermediate idea; so, to see the idea, do you need another intermediate idea? And so on, ad infinitum?
In explaining perception of objects, Locke has introduced perception of ideas—and that needs just as much explanation.
In placing a veil of perception in between the perceiving subject and the external world, the view is vulnerable to skepticism.
It’s very unclear whether Locke actually held this view, or if he did, what version he held.

23. Primary and secondary qualities
Locke does hold that, of our ideas, some do and some don’t resemble what causes them.
Primary and secondary qualities:
These are different kinds of qualities in external objects.
Primary: solidity, extension, figure, texture, motion, number
Inseparable from body.
Real qualities of bodies.
Our ideas of them do resemble something in bodies.
Secondary: colors, sounds, tastes
Depend on primary qualities (their arrangement, etc.)
Mere powers of bodies to produce ideas.
Our ideas of them don’t resemble anything in bodies.

24. Terminology
Unfortunately, Locke uses ‘Idea’ to stand for things in minds as well as things in bodies.
He does insist on this distinction—otherwise, we might not notice that our ideas might not resemble qualities in bodies.
So be clear:
‘Ideas’ are what the mind immediately perceives.
‘Qualities’ are things in a subject [body] that has the power to bring about ideas in us.
But (amazingly!) sometimes he still uses the word ‘Idea’ for qualities. He says you can figure out what he means.

25. Primary qualities They are “utterly inseparable from the Body”
Do whatever you want to it: “all the alterations and changes it suffers, all the force can be used upon it,” but primary qualities will remain.
You can divide up a bit of matter all you want, but it will still have primary qualities.
Even if you can’t see it, still your mind will find primary qualities inseparable from a bit of matter.
This is because division can do nothing to take away these qualities.
These qualities give us simple ideas:
Solidity, Extension, Figure, Motion-or-Rest, Number

26. Secondary qualities
They are mere powers in the objects—powers to produce sensations in us.
They are not real qualities in the objects.
Exercise of these powers is grounded in primary qualities.
“the Bulk, Figure, Texture, and Motion of their insensible parts”
Colors, sounds, tastes, etc.
There is also a third sort of quality: the power of one external object to produce changes in another external object.
Like the power of fire to melt wax.
These are on a par with secondary qualities.
Everyone sees that these are not real qualities, but mere powers grounded in the primary qualities of the object.

27. How bodies produce ideas in us
It happens “by impulse, the only way which we can conceive Bodies operate in”
Primary qualities send particles to our senses, and motion carries to our brains and our minds, producing ideas.
Likewise with secondary qualities: a violet causes an idea of blue color by means of tiny particles in motion.
Yes, the idea doesn’t resemble the causes.
But the idea of pain doesn’t resemble “steel dividing our flesh”
God can apparently connect non-resembling ideas to motions of particles.
So though we mistakenly take colors and smells to be real qualities in objects, they are mere powers depending on primary qualities.

28. Resemblance / mind-independence
There are real qualities of objects resembling our ideas of primary qualities.
But there isn’t anything in objects resembling our ideas of secondary qualities.
Mind-independence:
Primary qualities are in fire or snow whether anyone perceives them or not.
But secondary qualities go away when not perceived, nothing left but primary qualities.

29. Examples
Everyone agrees that pain isn’t in fire, so why do people think that warmth is in fire?
Everyone agrees that (say) motion and figure are in manna, and that pain and indigestion are not in manna, so why do people think sweetness and whiteness are in manna?
Porphyry loses its color in the dark—clearly light can’t make real changes in the porphyry, so the color isn’t a real quality.
Pounding an almond changes its secondary qualities, but pounding can only change texture!
With Locke’s account, we can explain why the same water can feel hot to one hand and cold to another.

30. Summary Remember the three kinds of qualities of bodies:
Mind-independent real qualities (primary)
Mere powers to produce ideas in us (secondary, usually called ‘sensible’)
Mere powers to produce changes in other bodies (usually called ‘powers’)
The last two are both mere powers.

31. Why do people go wrong?
Why do people think that secondary qualities are real qualities, when they know that the third qualities are mere powers? Why the double-standard?
When we see a body produce a change in another body, we can observe that the change doesn’t resemble anything in the first body.
But when a body produces ideas in us, we cannot compare the idea with the body to see if they resemble.
The connection between primary qualities and resulting ideas of secondary qualities is quite beyond our understanding.
So we presume that the ideas of secondary qualities resemble something in the object.

32. A few things to note Locke works with corpuscularianism.
On some interpretations, this is the reason why he rejects the reality of secondary qualities.
It’s because our best physical theory makes use of primary qualities only—physics has no need of color.
Locke is with the other mechanists.
Galileo, Hobbes, Descartes, Gassendi, Boyle had all drawn this distinction. Cartesians and atomists alike.
They all rejected the old Scholastic view of sensible qualities (bodies transmit (say) visible species to the mind, where it is an intelligible species; the quality inheres in the mind as well as in the body).

33. A few things to note
Locke does not say there are no colors, sounds, etc.
He seems to identify them with powers of the object—powers to produce ideas in us.
And these powers are grounded in the primary qualities.
This looks different from Descartes.
He points to two other kinds of qualities that people agree to be mere powers.
The power of one body to make changes in another (the change isn’t really in the first body).
The power of bodies to make us feel pain (the pain isn’t really in the body that is causing us pain).
Similarly, Locke thinks, colors and sounds are not really in bodies (except as mere powers).

34. Tinkering with simple ideas
While discussing ideas of reflection, he mentions some important mental faculties and operations.
Faculties
perception, contemplation, memory, discerning
Operations
Comparing: setting ideas alongside each other, seeing how they relate to each other
Compounding: putting ideas together
Abstracting: considering ideas separate from any overly specific circumstances
Animals
For each, he discusses whether animals have this faculty or can perform this operation.
Abstraction is the only one animals cannot do at all.

35. Locke’s scheme Ideas Simple ideas (experience)
sensation
reflection
Complex ideas (compounding)
of modes
simple modes
mixed modes
of substances
of relations (comparing)
General/abstract ideas (abstraction)