Mind’s Eye Idea Object - Homepages at WMUhomepages.wmich.edu/~baldner/locke3berkeley1f17.pdf• Objects outside our minds cause sensations in our minds. • Different properties

Do the ideas in our mind resemble the qualities in the objects that caused these ideas in our minds?

Mind’s Eye Idea Object

Does this …

…resemble this?

In Locke’s Terms

• Even if we accept that the ideas in our mindare caused by real objects that exist outside ourminds– (Locke never really questions this)

• Is it true that our ideas always resemble thequalities in the objects that caused us to havethose ideas?

Locke’s Answer

• Only sometimes. Some of our ideas doresemble qualities in the objects, but some ofthem do not.

• Our ideas of primary qualities resemble thosequalities.

• Our ideas of secondary qualities do not.

Why …?

• In sense experience, objects cause us to havesensations.

• Locke says that sensations don’t alwaysresemble the qualities of these objects.

• Why?• Why don’t our ideas always resemble the

qualities in the objects that cause us to havethose ideas?

Explaining the difference

Explaining Sensations

• We have scientific explanations for how objectscan cause us to have sensations.

• They explain how different properties in objectscause different kinds of sensations in us.– Exp.: Seeing red vs. seeing blue.

• Different qualities effect our sense organsdifferently, and cause different kinds of sensationsor ideas in our minds.

• These qualities need not resemble the sensationsthey cause.

Sensations as Effects

• So, sensations are the effects of causalinteractions with the world.

• But effects need not resemble their causes.– Smoke doesn’t resemble fire!

• Our sensations of color, sound, taste, smell,and temperature don’t resemble the qualities inthe object that cause us to have thosesensations.

So,• Objects outside our minds cause sensations in our

minds.• Different properties of objects cause different

kinds of sensations.• Science hypothesizes the properties objects must

really have to explain the ideas we have of them.• As long as a specific quality in the object

uniformly causes a certain kind of sensation in us,there is no reason that these qualities need toresemble the sensations that they cause.

Sensations of blue vs. the quality of being blue

• So, being blue (a secondary quality) is a propertyan object has because it has the “power” to causecertain kinds of ideas in our minds.– It has this “power” because of the primary qualities of

the particles out of which it is composed, and how theseparticles interact with our bodies in sense perception.

– So the “power,” or quality of being blue, is what causesus to have certain kinds of sensations, which we callsensations of blue.

Being Blue• So the “blueness” of a blue chair is “real,” but is

not a fundamental quality of the particles the chairis composed of.– The blueness of the chair is explained in terms of the

fundamental properties of the particles out of which it iscomposed.

– I.e., the secondary quality (of being blue) just is the qualityof being composed of particles with certain primaryqualities.

– This is what makes them secondary—they are explained interms of combination of more basic primary qualities.

Where did “Blue” go?

• Which is blue?– The sensation (idea) in our mind, or– The quality (power) in the object?

• Blue is a quality of objects.– Sensations aren’t blue, any more than they are

heavy!– Sensations are of blue.

“Stop me if you’ve heard this one ….”

Falling Trees– You’ve all heard this one:

• If a tree falls in the forest with no one thereto hear it, does it make any sound?

• How do you think Locke would answer thisquestion.

• What does science tell you?• Hint: The “correct” answer is: Yes and No.

Answer• The tree in the forest disturbs air waves whether or not

there is anyone there to hear it. (This is “realism.”)• But if no one is present, it doesn’t produce any

auditory sensations in anyone’s mind.• The confusion: We use the word “sound” both to talk

about airwaves and to talk about sensations.• But these are different things. The falling tree disturbs

air waves (makes a “sound” on one use), but doesn’tcause any sensations (doesn’t make a “sound,” on theother use).

A problem?• On this view, all we are ever directly conscious of in

sense experience are the ideas or sensations that exist inour minds.

• We cannot, even in principle, ever get “outside” our ownminds to see if we are correct about the objects, accordingto the theory, that cause our sensations.– We only see the effects, never the causes.

• So, how could we know for sure whether or not oursensations ever “resemble” their causes, or even if theseexternal objects even exist in the first place?

George Berkeley

The Principles of Human Knowledge

To beis

to be perceived

“Obvious to the Mind…”

• “… all those bodies which compose the earth … haveno… subsistence without a mind, … their being is tobe perceived or to be known” [Principle 6]– “their esse is percipi” [Principle 3]—their “being” is in

“being perceived.”• Trees, tables, human bodies, etc., exist only in being perceived;

exist only in our minds!

• “… it follows, there is not any substance other thanspirit, or that which perceives.” [Principle 7]

Berkeley’s Idealism:• There is no such thing as “material substance.”• Real things like tables, mountains, etc., exist only

in being perceived. Their esse (“being”) is percipi(“being perceived”).

• The only real substance is mental, i.e., the onlythings that exist in the universe are mind/souls(and the ideas that exist “in” them).

• “Things,” like tables and chairs, mountains andbodies, exist only in our perceptions of them.– They exist only in our minds.

Berkeley Rejects (Metaphysical) Realism

• Realists, like both Descartes and Locke,believe that there is a world (the materialworld) that exists independently of whether ornot any conscious mind experiences it.– Berkeley rejects this.• “there is not any substance other than spirit”

• Berkeley’s position is known as (metaphysical)idealism.

Mind/Body Dualism

• Descartes and Locke both believe that mind and body(matter) are two fundamentally distinct andirreducible kinds of basic “stuff” or substance thatconstitute the basic fabric of reality.– We’ll look at arguments for and against this position in our

next chapter.

• Dualists believe that minds or “souls” have a distinctexistence from the bodies (material objects) they“occupy.”

Berkeley Rejects Mind/Body Dualism

• “Dualists,” like both Descartes and Locke,believe that the world contains twofundamentally different kinds of “stuff”—mind and matter.

• Berkeley disagrees:• He believes in the existence of mind;

– “that which perceives”

• He does not believe in the existence of matter.

Berkeley

• Believes that, in the end, minds (souls, spirits,immaterial substances) are the only sorts ofthings that exist.

• Believes that “bodies” (all the things we canperceive with our senses) exist only in ourconsciousness of them—they are nothing but“collections of ideas.”

Locke’s Causal Theory of Perception:Indirectly aware of

Sensation

Matter

Berkeley simply REJECTS this part of Locke’s

picture.

Compare and Contrast

Locke:

• “Whatsoever the mind perceives in itself, or isthe immediate object of perception, thought,or understanding, that I call idea…”

• That is, Locke believes that in “perception,thought, [and] understanding,”—in all formsof conscious awareness—what we are“immediately aware” of are always/only ideasin our minds.

Berkeley:

• “It is evident … [that] the objects of humanknowledge … are either ideas actuallyimprinted on the senses, or else such as areperceived by attending to the … operationsof the mind … [such as] memory andimagination ….”

• Berkeley agrees that in all forms of consciousawareness, what we are “immediately aware” ofare always/only ideas in our minds.

Locke and Berkeley Agree:

• The only immediateobjects of thoughts,sensations,perceptions, etc. (ofany consciousexperience) are ideasor sensations, i.e.,things that exist onlyin our minds.

Where they disagree:Is there any world beyond (independent

of) our ideas?

• Locke: Yes.• Berkeley: No.

Berkeley’s Idealism

Berkeley’s View:

• Objects (tables, chairs, bodies, etc) aresimply “collections of ideas” that exist onlyin being perceived.– This is Berkeley’s Idealism.

Real objects are collectionsof ideas.

Defending Idealism byRejecting Materialism

Berkeley’s Idealism: There is only onefundamental kind of thing, mental things, i.e., minds or souls (and the ideas that are ‘in’ them).

(What Berkeley calls) Materialism:The view that there are material things (that there is a “material substance”) in

addition to mental things.This is what we called “dualism.” Later

philosophers will use the term “materialism” for those who accept matter but deny mental substance.

Berkeley’s Claim:Materialism leads to skepticism

• Even if it is “possible that solid, figured, moveablesubstances … exist without the mind,– yet how is it possible for us to know this?”

• If all that we directly know or experience are ideasin the mind (mental entities), we have no evidencefor the existence of anything distinct from theseideas.

• We are directly aware only of ideas.• Locke: We infer material objects as the causes of

these ideas.• Berkeley challenges this inference.

Directly Known Material Substance:

Only inferred

Even if we grant that we don’t directly perceive material substances, can’t we infer them as the best explanation of the ideas and

sensations that we do perceive?

• Berkeley: But “by their own confession …they own themselves unable to comprehendin what manner body can act upon spirit.”

--i.e., positing the existence of matter doesn’t really explain anything, since you can’t actually explain how matter causally influences mind.

“they [are] unable to … [explain how] body can act upon spirit.”

• For Dualists (like Locke and Descartes), mind andmatter are two distinct kinds of substances—theyhave nothing in common.

• But if they have nothing in common, how can theycausally interact with one another?– How can mind (“spirit”) make matter move?– How can matter (“body”) cause ideas in a (non-material)

mind?

Berkeley: How could mind causally interact with matter?

?