EmpiricismEmpiricismEmpiricismEmpiricism

Concept Empiricism• All concepts from experience;

none innate• Hume: “. . . all our ideas are

nothing but copies of our impressions, or, in other words, that it is impossible for us to think of anything, which we have not antecedently felt, either by our external or internal senses.”

Judgment Empiricism• All knowledge of the

world comes from experience

• There are no synthetic a priori truths

Concept —> Judgment• Locke: “Had those who would persuade us that there are innate

principles not taken them together in gross, but considered separately the parts out of which those propositions are made, they would not, perhaps, have been so forward to believe they were innate. Since, if the ideas which made up those truths were not, it was impossible that the propositions made up of them should be innate, or our knowledge of them be born with us. For, if the ideas be not innate, there was a time when the mind was without those principles; and then they will not be innate, but be derived from some other original. For, where the ideas themselves are not, there can be no knowledge, no assent, no mental or verbal propositions about them.”

Two Kinds of Experience• Sensation

– Vision– Hearing– Smell– Taste– Touch

• Reflection

Kinds of experience10

• Locke: “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:- How comes it to be furnished? Whence comes it by that vast store which the busy and boundless fancy of man has painted on it with an almost endless variety? Whence has it all the materials of reason and knowledge? To this I answer, in one word, from EXPERIENCE. In that all our knowledge is founded; and from that it ultimately derives itself. Our observation employed either, about external sensible objects, or about the internal operations of our minds perceived and reflected on by ourselves, is that which supplies our understandings with all the materials of thinking. These two are the fountains of knowledge, from whence all the ideas we have, or can naturally have, do spring.”

Distinctions• Impressions —> Ideas

– Impressions: received by external or internal senses

– Ideas are copies of impressions

• Simple & Complex Impressions and Ideas– Complex ideas are compounds

of other ideas– Simple ideas aren’t

Simple Ideas• Simple ideas

– come from simple impressions

– Represent them exactly

• Hume: "all our simple ideas in their first appearance are deriv'd from simple impressions, which are correspondent to them, and which they exactly represent."

Empiricists’ Method• Analyze complex ideas

into simple ideas• Find origins of simple

ideas in experience• Content of the idea lies in

simple impression(s) from which it comes

Hume’s Statement• “All ideas, especially abstract ones, are naturally faint and obscure:

The mind has but a slender hold of them: They are apt to be confounded with other resembling ideas; and when we have often employed any term, though without a distinct meaning, we are apt to imagine it has a determinate idea, annexed to it. On the contrary, all impressions, that is, all sensations, either outward or inward, are strong and vivid: The limits between them are more exactly determined: Nor is it easy to fall into any error or mistake in regard to them. When we entertain, therefore, any suspicion, that a philosophical term is employed without any meaning or idea (as is but too frequent), we need but enquire, from what impression is that supposed idea derived? And if it be impossible to assign any, this will serve to confirm our suspicion. By bringing ideas into so clear a light, we may reasonably hope to remove all dispute, which may arise, concerning their nature and reality.”

Kinds of Knowledge20

• Analytic a priori:– Logic– Definitions– Mathematics

• Synthetic a posteriori– Natural science

Test for Nonsense• Hume: “When we run over libraries, persuaded of

these principles, what havoc must we make? If we take in our hand any volume; of divinity or school metaphysics, for instance; let us ask, Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence? No. Commit it then to the flames: For it can contain nothing but sophistry and illusion.”

Arguments for Rationalism• Universality

– All experience is particular– Particular -/-> universal

• Necessity– All experience is

contingent– Contingent -/-> necessary

Universality• We move from particular to universal in

induction– Instances —> generalization

• What justifies this move?– It doesn’t follow; not logic– Rationalist: innate idea or principle– Hume: nothing

Inductive Inferences

• All observed ravens have been black; so, all ravens are black

• When I’ve eaten bread, I’ve found it nourishing; so, bread is nourishing

• When the sun sets, it rises the next morning; so, the sun always rises

Scandal of Induction30

• Justification for inductive reasoning is not a priori– Not necessary; the next raven might be

white

• Justification is not a posteriori– That would be an appeal to experience– But that’s just what’s at issue!

Hume’s Circle• “We have said, that all arguments concerning

existence are founded on the relation of cause and effect; that our knowledge of that relation is derived entirely from experience; and that all our experimental conclusions proceed upon the supposition, that the future will be conformable to the past. To endeavor, therefore, the proof of this last supposition by probable arguments, or arguments regarding existence, must be evidently going in a circle, and taking that for granted, which is the very point in question.”

Hume’s Tangent• “. . . after the constant conjunction of two objects, heat and flame,

for instance, weight and solidity, we are determined by custom alone to expect the one from the appearance of the other. This hypothesis seems even the only one, which explains the difficulty, why we draw, from a thousand instances, an inference, which we are not able to draw from one instance, that is, in no respect, different from them. Reason is incapable of any such variation. The conclusions, which it draws from considering one circle, are the same which it would form upon surveying all the circles in the universe. But no man, having seen only one body move after being impelled by another, could infer, that every other body will move after a like impulse. All inferences from experience, therefore, are effects of custom, not of reasoning.”

Hume’s Sceptical Solution

• There is no rational justification for inductive inference

• Based on habit or custom, not reason

Necessity• We make causal

inferences:– Cause —> effect– Effect —> cause

• What justifies them?– Not a priori: We can

imagine it otherwise– Not a posteriori: We don’t

experience the causal link

Necessity40

• “When we look about us towards external objects, and consider the operation of causes, we are never able, in a single instance, to discover any power or necessary connexion; any quality, which binds the effect to the cause, and renders the one an infallible consequence of the other. We only find, that the one does actually, in fact, follow the other. The impulse of one billiard-ball is attended with motion in the second. This is the whole that appears to the outward senses. . . .

• So that, upon the whole, there appears not, throughout all nature, any one instance of connexion which is conceivable by us. All events seem entirely loose and separate. One event follows another; but we never can observe any tie between them. They seem conjoined, but never connected.”

Instances• From one instance, we can infer

nothing

• From repeated instances, we infer causal link

• But nothing in the world changes

• What does? Our feeling of expectation.

Origin of idea of causation45

• Constant conjunction of events —>

• Feeling of expectation (internal impression) —>

• Ideas of causation and necessity

The source within

• Necessity and causation aren’t in the world

• These ideas come from something in us

• “Necessity . . . Exists in the mind, not in objects.”

• We project regularity onto the world

Projection

• “'Tis a common observation, that the mind has a great propensity to spread itself on external objects, and to conjoin with them any internal impressions, which they occasion, and which always make their appearance at the same time that these objects discover themselves to the senses.”