Hume’s Central PrinciplesHume’s Central Principles

Peter MillicanPeter Millican

Hertford College, OxfordHertford College, Oxford

4. Hume on Induction4. Hume on Induction

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From the IdeaFrom the Ideaof Causationof Causationtoto Induction Induction

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The Idea of CausationThe Idea of Causation

To understand reasoning to the unobserved To understand reasoning to the unobserved (i.e. (i.e. probableprobable reasoning, though Hume has reasoning, though Hume has not yet used the term), “we must consider the not yet used the term), “we must consider the idea of idea of causationcausation, and see from what origin it , and see from what origin it is deriv’d” (is deriv’d” (TT 1.3.2.4). 1.3.2.4).

The search for the origin of this idea will The search for the origin of this idea will shape the remainder of shape the remainder of TreatiseTreatise 1.3. 1.3.

There is no specific quality that characterises There is no specific quality that characterises causes and effects, so it must be some causes and effects, so it must be some relationrelation between the two. ( between the two. (TT 1.3.2.5-6) 1.3.2.5-6)

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Contiguity and PriorityContiguity and Priority

We find causes and effects to be We find causes and effects to be contiguouscontiguous in space and time (in space and time (TT 1.3.2.6), though a 1.3.2.6), though a footnote hints at a significant reservation footnote hints at a significant reservation (explored in (explored in TT 1.4.5 which points out that 1.4.5 which points out that many perceptions have no spatial location).many perceptions have no spatial location).

We also find causes to be We also find causes to be priorprior to their to their effects (effects (TT 1.3.2.7), though again Hume 1.3.2.7), though again Hume seems to indicate that this isn’t a particularly seems to indicate that this isn’t a particularly crucial matter (crucial matter (TT 1.3.2.8). 1.3.2.8).

There still seems to be something missing … There still seems to be something missing …

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Necessary ConnexionNecessary Connexion

There follows a famous passage, which is There follows a famous passage, which is commonly misunderstood:commonly misunderstood:

““Shall we then rest contented with these two Shall we then rest contented with these two relations of contiguity and succession, as relations of contiguity and succession, as affording a compleat idea of causation? By no affording a compleat idea of causation? By no means. An object may be contiguous and prior to means. An object may be contiguous and prior to another, without being consider’d as its cause. another, without being consider’d as its cause. There is a There is a NECESSARY CONNEXIONNECESSARY CONNEXION to be taken to be taken into consideration; and that relation is of much into consideration; and that relation is of much greater importance, than any of the other two greater importance, than any of the other two above-mention’d.” (above-mention’d.” (TT 1.3.2.11) 1.3.2.11)

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To Neighbouring FieldsTo Neighbouring Fields

Hume is looking for the crucial extra Hume is looking for the crucial extra component (component (beyond beyond single-casesingle-case contiguity contiguity and successionand succession) that makes up our idea of ) that makes up our idea of cause and effectcause and effect

It seems elusive, so he proceeds like those It seems elusive, so he proceeds like those who “beat about all the neighbouring fields, who “beat about all the neighbouring fields, without any certain view or design, in hopes without any certain view or design, in hopes their good fortune will at last guide them to their good fortune will at last guide them to what they search for” (what they search for” (TT 1.3.2.13). 1.3.2.13).

There are two such fields …There are two such fields …

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The Causal MaximThe Causal Maxim

The first field is the Causal Maxim:The first field is the Causal Maxim:

“’“’Tis a general maxim in philosophy, that Tis a general maxim in philosophy, that whatever begins to exist, must have a cause of whatever begins to exist, must have a cause of existenceexistence” (” (TT 1.3.3.1) 1.3.3.1)

Hume argues that this is neither intuitively nor Hume argues that this is neither intuitively nor demonstratively certain (demonstratively certain (TT 1.3.3.1-8) 1.3.3.1-8)

““Since it is not from knowledge or any scientific Since it is not from knowledge or any scientific reasoning, that we derive [this] opinion …, [it] reasoning, that we derive [this] opinion …, [it] must necessarily arise from observation and must necessarily arise from observation and experience. …experience. … ( (TT 1.3.3.9) 1.3.3.9)

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Leading Up to InductionLeading Up to Induction

TreatiseTreatise 1.3.4 argues that causal reasoning, 1.3.4 argues that causal reasoning, if it is to result in real belief, must start from if it is to result in real belief, must start from something perceived or remembered.something perceived or remembered.

TT 1.3.5.1 sets out a corresponding agenda: 1.3.5.1 sets out a corresponding agenda:““Here therefore we have three things to explain, Here therefore we have three things to explain, viz. viz. FirstFirst, The original impression. , The original impression. SecondlySecondly, , The transition to the idea of the connected The transition to the idea of the connected cause or effect. cause or effect. ThirdlyThirdly, The nature and , The nature and qualities of that idea.”qualities of that idea.”

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““Of the impressionsOf the impressionsof the senses and memory”of the senses and memory”

The title of The title of TreatiseTreatise 1.3.5 seems odd, since 1.3.5 seems odd, since memory presents memory presents ideasideas, not , not impressionsimpressions..

But Hume’s main point here is that the But Hume’s main point here is that the perceptions of the senses and memory are alike perceptions of the senses and memory are alike in being more in being more strong and livelystrong and lively – having more – having more force and vivacityforce and vivacity – than the ideas of the – than the ideas of the imagination.imagination.

That force and vivacity, apparently, is what That force and vivacity, apparently, is what enables them to act as a “foundation of that enables them to act as a “foundation of that reasoning, which we build … when we trace the reasoning, which we build … when we trace the relation of cause and effect” (relation of cause and effect” (TT 1.3.5.7) 1.3.5.7)

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Recap – the road to Recap – the road to TreatiseTreatise 1.3.6 1.3.6

Recall Hume’s aim here:Recall Hume’s aim here:– He is seeking to understand our idea of He is seeking to understand our idea of

necessary connexion (cf. necessary connexion (cf. TT 1.3.2.11). 1.3.2.11).– This leads him to ask “Why we conclude, that This leads him to ask “Why we conclude, that

… particular causes must necessarily have … … particular causes must necessarily have … particular effects, and why we form an particular effects, and why we form an inference from one to another?” (inference from one to another?” (TT 1.3.3.9). 1.3.3.9).

– The key part of this process is “the inference The key part of this process is “the inference from the impression to the idea” (cf. from the impression to the idea” (cf. TT 1.3.5.1); 1.3.5.1); call this “causal inference” for short.call this “causal inference” for short.

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The Argument The Argument concerningconcerning InductionInduction

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The Famous Argument (×3)The Famous Argument (×3)

TreatiseTreatise 1.3.6 contains the famous argument 1.3.6 contains the famous argument concerning induction, though Hume doesn’t concerning induction, though Hume doesn’t seem entirely to appreciate its significance – seem entirely to appreciate its significance – it is mainly a staging post in his search for the it is mainly a staging post in his search for the origin and nature of our idea of causation.origin and nature of our idea of causation.

In the In the AbstractAbstract of 1740 it is elevated to a of 1740 it is elevated to a much more prominent position, as the centre-much more prominent position, as the centre-piece of Hume’s “Chief Argument”.piece of Hume’s “Chief Argument”.

The fullest and clearest version is in the first The fullest and clearest version is in the first EnquiryEnquiry, Section 4., Section 4.

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Streamlining the ArgumentStreamlining the Argument

In the In the TreatiseTreatise, Hume, Hume’s focus is on ’s focus is on causalcausal inference “from the impression to the idea”inference “from the impression to the idea”..

In the In the AbstractAbstract and and EnquiryEnquiry, he broadens it to , he broadens it to ask about the foundation of “all reasonings ask about the foundation of “all reasonings concerning concerning matter of factmatter of fact” (” (AA 8): 8):

““What is the nature of that evidWhat is the nature of that evidence, which assures ence, which assures us of any real existence and matter of fact, beyond us of any real existence and matter of fact, beyond the present testimony of our senses, or the records the present testimony of our senses, or the records of our memory.of our memory.” (” (EE 4.3) 4.3)

His first pHis first point is that all such [inductive] inference oint is that all such [inductive] inference depends on depends on causalcausal relations ( relations (AA 8, 8, EE 4.4). 4.4).

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Causal Inference Is Not A Priori (1)Causal Inference Is Not A Priori (1)

In the In the TreatiseTreatise, Hume starts from causal , Hume starts from causal inference, arguinference, arguinging that this cannot be a priori, that this cannot be a priori, just because we can just because we can conceiveconceive of things coming of things coming out differently (out differently (TT 1.3.6.1). 1.3.6.1).

HerHeree he evinces the [common, but not obvious] he evinces the [common, but not obvious] assumption that any a priori inference would assumption that any a priori inference would have to yield complete certainty.have to yield complete certainty.

“’“’Tis therefore by EXPERIENCE only, that we Tis therefore by EXPERIENCE only, that we can infer the existence of one object from that can infer the existence of one object from that of another” (of another” (TT 1.3.6.2). 1.3.6.2).

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A Thought ExperimentA Thought Experiment

In the In the AbstractAbstract and and EnquiryEnquiry, Hume imagines, Hume imagines Adam, newly created by God, trying to Adam, newly created by God, trying to envisage the effect of a billiard-ball collision:envisage the effect of a billiard-ball collision:

– how could he possibly how could he possibly make any prediction at all make any prediction at all in advance of experience?in advance of experience?

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Causal Inference Is Not A Priori (2)Causal Inference Is Not A Priori (2)

Here also Hume’s subsequent argument is Here also Hume’s subsequent argument is stronger, because he doesn’t rely just on stronger, because he doesn’t rely just on conceivabilityconceivability, but puts more emphasis on , but puts more emphasis on arbitrarinessarbitrariness::

““Were any object presented to us, and were we Were any object presented to us, and were we required to pronounce concerning the effect, which required to pronounce concerning the effect, which will result from it, without consulting past observation; will result from it, without consulting past observation; after what manner, I beseech you, must the mind after what manner, I beseech you, must the mind proceed in this operation? It must invent or imagine proceed in this operation? It must invent or imagine some event, which it ascribes to the object as its some event, which it ascribes to the object as its effect; and it is plain that this invention must be effect; and it is plain that this invention must be entirely entirely arbitraryarbitrary. …. …” (” (EE 4.9) 4.9)

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Experience and Constant ConjunctionExperience and Constant Conjunction

The kind of experience on which causal The kind of experience on which causal inference is based is repeated patterns of inference is based is repeated patterns of one thing, one thing, AA, followed by another, , followed by another, BB::

““Without any farther ceremony, we call the one Without any farther ceremony, we call the one causecause and the other and the other effecteffect, and infer the existence , and infer the existence of the one from that of the other.” (of the one from that of the other.” (TT 1.3.6.2) 1.3.6.2)

““Thus … we have … discover’d a new Thus … we have … discover’d a new relation betwixt cause and effect, when we relation betwixt cause and effect, when we least expected it … This relation is their least expected it … This relation is their CONSTANT CONJUNCTIONCONSTANT CONJUNCTION.” (.” (TT 1.3.6.3) 1.3.6.3)

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““Perhaps ’twill appear in the end …”Perhaps ’twill appear in the end …”

The capitalisation in The capitalisation in TT 1.3.6.3 clearly links back 1.3.6.3 clearly links back to to TT 1.3.2.11, as does the text: 1.3.2.11, as does the text:

““Contiguity and succession are not sufficient to make Contiguity and succession are not sufficient to make us pronounce any two objects to be cause and effect, us pronounce any two objects to be cause and effect, unless … these two relations are preserv’d in several unless … these two relations are preserv’d in several instances [i.e. there’s a constant conjunction].”instances [i.e. there’s a constant conjunction].”

But how can this give rise to the new idea of But how can this give rise to the new idea of necessary connexion? Anticipating necessary connexion? Anticipating TT 1.3.14.20, 1.3.14.20,

““Perhaps ’twill appear in the end, that the necessary Perhaps ’twill appear in the end, that the necessary connexion depends on the inference, instead of the connexion depends on the inference, instead of the inference’s depending on the necessary connexion”.inference’s depending on the necessary connexion”.

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A Question of FacultiesA Question of Faculties

Since causal reasoning from [impression of] Since causal reasoning from [impression of] cause cause AA to [idea of] effect to [idea of] effect BB is founded on is founded on “past “past experienceexperience, and … remembrance of … , and … remembrance of … constant conjunctionconstant conjunction” (” (TT 1.3.6.4), 1.3.6.4),

““the next question is, whether experience the next question is, whether experience produces the idea [of the effect produces the idea [of the effect BB] by means of ] by means of the the understandinunderstanding or g or imaginationimagination; whether we are ; whether we are determin’d by determin’d by reasonreason to make the transition, or by to make the transition, or by a certain association and relation of a certain association and relation of perceptions?”perceptions?”

Hume will now argue that it can’t be reason.Hume will now argue that it can’t be reason.

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The Need for ExtrapolationThe Need for Extrapolation

[All inference to matters of fact beyond what [All inference to matters of fact beyond what we perceive or remember seems to be based we perceive or remember seems to be based on causation, and] all our knowledge of on causation, and] all our knowledge of causal relations comes from experience.causal relations comes from experience.

Such learning from experience takes for Such learning from experience takes for granted that observed phenomena provide a granted that observed phenomena provide a guide to unobserved phenomena.guide to unobserved phenomena.

We thus We thus extrapolateextrapolate from past to future on from past to future on the assumption that they resemble. But do the assumption that they resemble. But do we have a rational basis for doing so?we have a rational basis for doing so?

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UP: The Uniformity PrincipleUP: The Uniformity Principle

Hume then focuses on the principle (UP) Hume then focuses on the principle (UP) presupposed by such extrapolation:presupposed by such extrapolation:– ““If reason determin’d us, it wou’d proceed upon that If reason determin’d us, it wou’d proceed upon that

principle, principle, that instances of which we have had no that instances of which we have had no experience, must resemble those of which we have experience, must resemble those of which we have had experience, and that the course of nature had experience, and that the course of nature continues always uniformly the samecontinues always uniformly the same.” (.” (TT 1.3.6.4) 1.3.6.4)

– This seems This seems conditionalconditional: : IFIF reason is involved, reason is involved, THENTHEN it must be based on this principle. it must be based on this principle.

– But later: “probability But later: “probability isis founded on the presumption founded on the presumption of a resemblance …” (of a resemblance …” (TT 1.3.6.7) 1.3.6.7)

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UP in the UP in the EnquiryEnquiry

In the In the EnquiryEnquiry is less explicitly stated: is less explicitly stated:– ““all our experimental [experiential] conclusions all our experimental [experiential] conclusions

proceed upon the supposition, that the future proceed upon the supposition, that the future will be conformable to the past”. (will be conformable to the past”. (EE 4.19) 4.19)

– No suggestion of conditionality (cf. also No suggestion of conditionality (cf. also EE 5.2: 5.2: “in “in allall reasonings from experience, reasonings from experience, there is a there is a step taken by the mindstep taken by the mind” corresponding to UP).” corresponding to UP).

– Vaguer than original Vaguer than original TreatiseTreatise UP, and so more UP, and so more plausible: we expect the future to “resemble” plausible: we expect the future to “resemble” ((EE 4.21) the past, but not copy exactly. 4.21) the past, but not copy exactly.

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The Role of the Uniformity PrincipleThe Role of the Uniformity Principle

Hume need not be suggesting that we think of Hume need not be suggesting that we think of UP UP explicitlyexplicitly when making inductive inferences when making inductive inferences (and (and TT 1.3.8.13 says typically we don’t). 1.3.8.13 says typically we don’t).

Rather, in making an inductive inference, we Rather, in making an inductive inference, we manifestmanifest the assumption of UP, in basing our the assumption of UP, in basing our inferential behaviour on past experience.inferential behaviour on past experience.– So inferring from past to future is So inferring from past to future is ipso factoipso facto treating treating

“the past [as a] rule for the future” (cf. “the past [as a] rule for the future” (cf. EE 4.21) 4.21)– Hence the question arises: Hence the question arises: can this assumption be can this assumption be

founded on reasonfounded on reason, or is there some other , or is there some other explanation for why we make it?explanation for why we make it?

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Can UP be Founded on Argument?Can UP be Founded on Argument?

After stating UP in the After stating UP in the TreatiseTreatise, Hume , Hume immediately continues:immediately continues:

““In order therefore to clear up this matter, let us In order therefore to clear up this matter, let us consider all the arguments, upon which such a consider all the arguments, upon which such a proposition may be suppos’d to be foundedproposition may be suppos’d to be founded; and ; and as these must be deriv’d either from as these must be deriv’d either from knowledgeknowledge or or probabilityprobability, let us cast our eye on each of these , let us cast our eye on each of these degrees of evidence, and see whether they afford degrees of evidence, and see whether they afford any just conclusion of this nature.” (any just conclusion of this nature.” (TT 1.3.6.4) 1.3.6.4)

By By knowledgeknowledge, Hume means , Hume means demonstrationdemonstration, , as becomes evident in the next sentence.as becomes evident in the next sentence.

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Both Both forms of argument are quickly ruled out, forms of argument are quickly ruled out, demonstrationdemonstration by the Conceivability Principle: by the Conceivability Principle:

““We can at least conceive a change in the course of We can at least conceive a change in the course of naturenature; which … proves, that such a change is not ; which … proves, that such a change is not absolutely impossible [and thus] a refutation of any absolutely impossible [and thus] a refutation of any pretended demonstration against it.” (pretended demonstration against it.” (TT 1.3.6.5) 1.3.6.5)

And And probableprobable argument by circularity: argument by circularity:““pprobability … is founded on the presumption of a robability … is founded on the presumption of a resemblance betwixt those objects, of which we resemblance betwixt those objects, of which we have had experience, and those, of which we have have had experience, and those, of which we have had note; and therefore ’tis impossible this had note; and therefore ’tis impossible this presumption can aripresumption can arise from probability.” (se from probability.” (TT 1.3.6.7) 1.3.6.7)

(Hume first argues, at (Hume first argues, at TT 1.3.6.6-7, that probable 1.3.6.6-7, that probable argument is causal and hence dependent on UP.)argument is causal and hence dependent on UP.)

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EnquiryEnquiry More Complete More Complete

At At TT 1.3.6.4, 1.3.6.4, HumeHume assumes that assumes that demon-demon-strationstration and and probabilityprobability are the only possible are the only possible foundations for UPfoundations for UP; but; but in the in the EnquiryEnquiry, he , he also rules out also rules out sensationsensation and and intuitionintuition::

““ththere is no known connexion between the ere is no known connexion between the sensible qualities and the secret powers; and sensible qualities and the secret powers; and consequently, … the mind is not led to form such consequently, … the mind is not led to form such a conclusion concerning their constant and a conclusion concerning their constant and regular conjunction, by any thing which it knows regular conjunction, by any thing which it knows of their nature.” (of their nature.” (EE 4.16) 4.16)

““The connexion … is not intuitive.” (The connexion … is not intuitive.” (EE 4.16) 4.16)

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The “Sceptical” ConclusionThe “Sceptical” Conclusion

““even after experience has inform’d us of [causal]even after experience has inform’d us of [causal] constant conjunctionconstant conjunction, ’tis impossible for us to satisfy , ’tis impossible for us to satisfy ourselves by our reason, why we shou’d extend that ourselves by our reason, why we shou’d extend that experience beyond those particular instances, which experience beyond those particular instances, which have fallen under our observation.” (have fallen under our observation.” (TT 1.3.6.11) 1.3.6.11)

““even after we have experience of the operations of even after we have experience of the operations of cause and effect, our conclusions from that cause and effect, our conclusions from that experience are experience are notnot founded on reasoning, or any founded on reasoning, or any process of the understanding” (process of the understanding” (EE 4.15) 4.15)

““in all reasonings from experience, there is a step in all reasonings from experience, there is a step taken by the mind, which is not supported by any taken by the mind, which is not supported by any argument or process of the understanding” (argument or process of the understanding” (EE 5.2) 5.2)

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Argument Summary (in 2 Slides)Argument Summary (in 2 Slides)

The essential logic of the argument can be The essential logic of the argument can be represented using the “founded on” represented using the “founded on” relation (FO), together with:relation (FO), together with:

p Probable inference (to the unobserved)p Probable inference (to the unobserved)

c Causal reasoningc Causal reasoning

e (Reasoning from) Experiencee (Reasoning from) Experience

u Uniformity Principleu Uniformity Principle

R ReasonR Reason

d Demonstrationd Demonstration

i Intuitioni Intuition

s Sensations Sensation

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FO(c,e)

FO(p,u)

¬FO(p,R)

FO(e,u)

¬FO(u,s)

¬FO(u,d)

¬FO(u,R)¬FO(u,i)

¬FO(u,p)

FO(p,c)

FO(p,e)

Hume’s Argument Hume’s Argument concerning concerning

InductionInduction

Only in Only in EnquiryEnquiry

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Four “Kinds of Evidence” (Again)Four “Kinds of Evidence” (Again)

So the So the EnquiryEnquiry argument implicitly reasons: argument implicitly reasons:

¬FO(u,s) & ¬FO(u,i) & ¬FO(u,d) & ¬FO(u,p) ¬FO(u,s) & ¬FO(u,i) & ¬FO(u,d) & ¬FO(u,p) ¬FO(u,R) ¬FO(u,R)

If UP isn’t founded on sensation, intuition, demonstration If UP isn’t founded on sensation, intuition, demonstration or probable inference, then it isn’t founded on Reason.or probable inference, then it isn’t founded on Reason.

Compare this passage from Hume’s Compare this passage from Hume’s Letter Letter from a Gentlemanfrom a Gentleman (1745): (1745):

““It is common for Philosophers to distinguish the It is common for Philosophers to distinguish the Kinds of Evidence into Kinds of Evidence into intuitiveintuitive, , demonstrativedemonstrative, , sensiblesensible, and , and moral”moral”

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Debating Hume’s ArgumentDebating Hume’s Argument

A catalogue of recent interpretations:A catalogue of recent interpretations:– Flew 1961, Stove 1965/73: Flew 1961, Stove 1965/73: deductivismdeductivism;;– Stroud 1977: Stroud 1977: extreme scepticismextreme scepticism;;– Beauchamp & Mappes 1975, Winters 1979, B’p Beauchamp & Mappes 1975, Winters 1979, B’p

& Rosenberg 1981, Arnold 1983, Broughton & Rosenberg 1981, Arnold 1983, Broughton 1983, Craig 1987, Baier 1991: 1983, Craig 1987, Baier 1991: refuting refuting deductivism (hence “anti-deductivist”)deductivism (hence “anti-deductivist”);;

– Millican 1995/2002: Millican 1995/2002: anti-perceptual-insightanti-perceptual-insight;;– Garrett 1997: Garrett 1997: not founded on not founded on reasoningreasoning;;– Owen 1999: Owen 1999: anti-stepwise-inferenceanti-stepwise-inference;;– Millican 2011: Millican 2011: not founded on not founded on cognitioncognition..

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What Does “Reason” Mean?What Does “Reason” Mean?

By far the most significant distinction By far the most significant distinction between these interpretations is in terms of between these interpretations is in terms of their view of “reason” or “the understanding”:their view of “reason” or “the understanding”:– Flew, Stove: deductive reasoning onlyFlew, Stove: deductive reasoning only– Stroud: traditional “self-conscious” conceptionStroud: traditional “self-conscious” conception– Beauchamp Beauchamp et et al.: deductivist – but rejectedal.: deductivist – but rejected– Millican 1995: perceptual insight – but rejectedMillican 1995: perceptual insight – but rejected– Garrett: reason is the Garrett: reason is the reasoning reasoning facultyfaculty– Owen: intermediate steps – but rejectedOwen: intermediate steps – but rejected– Millican 2011: reason is the Millican 2011: reason is the cognitive cognitive facultyfaculty

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Inductive Inferences as “Reason”Inductive Inferences as “Reason”

“… “… with regard to with regard to reason reason … The only conclusion … The only conclusion we can draw from the existence of one thing to that we can draw from the existence of one thing to that of another, is by means of the relation of cause of another, is by means of the relation of cause and effect …” (and effect …” (T T 1.4.2.47) 1.4.2.47)

“… “… reason, in a strict and philosophical sense, can reason, in a strict and philosophical sense, can have an influence on our conduct … by informing have an influence on our conduct … by informing us of the existence of something which is a proper us of the existence of something which is a proper object of [a passion]; or when it discovers the object of [a passion]; or when it discovers the connexion of causes and effects, so as to afford us connexion of causes and effects, so as to afford us means of exerting any passion.” (means of exerting any passion.” (T T 3.1.1.12) 3.1.1.12)

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Reducing the FieldReducing the Field

Hume is not an extreme, undiscriminating Hume is not an extreme, undiscriminating sceptic but a keen advocate of inductive sceptic but a keen advocate of inductive science. So unless Hume is radically incon-science. So unless Hume is radically incon-sistent, Flew/Stove/Stroud must be wrong.sistent, Flew/Stove/Stroud must be wrong.

Ruling out a probable foundation for UP would Ruling out a probable foundation for UP would be otiose if “reason” were deductivist, so be otiose if “reason” were deductivist, so Beauchamp Beauchamp et al.et al. must also be wrong. must also be wrong.

Millican 1995 and Owen face the objection that Millican 1995 and Owen face the objection that Hume does not apparently Hume does not apparently rejectreject the view of the view of reason operative in his argument.reason operative in his argument.

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Agreeing with Garrett …Agreeing with Garrett …

Don Garrett and I now agree on a fair Don Garrett and I now agree on a fair number of points:number of points:– Hume’s “reason” is not Hume’s “reason” is not ambiguousambiguous (a point on (a point on

which he stood alone for many years);which he stood alone for many years);– Hume sees no obligation to prove our faculties Hume sees no obligation to prove our faculties

reliable a priori (rejectreliable a priori (rejectinging the burden of proof the burden of proof implied by “antecedent” scepticism – implied by “antecedent” scepticism – EE 12.3); 12.3);

– The logic of his argument is incompatible with The logic of his argument is incompatible with most previous interpretations (most obviously most previous interpretations (most obviously the deductivist and anti-deductivist).the deductivist and anti-deductivist).

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… … Up to a PointUp to a Point

However the key disagreement remains the However the key disagreement remains the nature of Humean “reason”:nature of Humean “reason”:– Garrett says “for Hume [as for Locke], reason is Garrett says “for Hume [as for Locke], reason is

the faculty of reasoning: of making inferences, or the faculty of reasoning: of making inferences, or providing, appreciating, and being moved by providing, appreciating, and being moved by arguments.” (1997, p. 27)arguments.” (1997, p. 27)

– I think “reason” is the overall I think “reason” is the overall cognitivecognitive faculty, just faculty, just another word for “the understanding” or the another word for “the understanding” or the “intellectual faculties”.“intellectual faculties”.

This is dThis is discussed in detail in my 2011 paper, iscussed in detail in my 2011 paper, “Hume’s ‘Scepticism’ about Induction”“Hume’s ‘Scepticism’ about Induction”..

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““Reason” and “Reasoning”Reason” and “Reasoning”

We tend to hear “reasoning”, “proof” and We tend to hear “reasoning”, “proof” and “argument” as implying “argument” as implying stepwisestepwise inference inference or or ratiocinationratiocination, but this is anachronistic., but this is anachronistic.

Johnson in 1756 defines “argument” as:Johnson in 1756 defines “argument” as:– ““A reason alleged for or against any thing.”A reason alleged for or against any thing.”

A A non-discursivenon-discursive sense of “reason” is: sense of “reason” is:– ““Argument; ground of persuasion, motive.”Argument; ground of persuasion, motive.”

And the first sense of “proof” is:And the first sense of “proof” is:– ““Evidence; testimony; convincing token.”Evidence; testimony; convincing token.”

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““Deduction” and “Ratiocination”Deduction” and “Ratiocination”

For For stepwisestepwise inference, Johnson prefers inference, Johnson prefers the terms “deduction” and “ratiocination”. the terms “deduction” and “ratiocination”. He gives as He gives as discursivediscursive senses of “reason”: senses of “reason”:– ““The power by which man deduces one The power by which man deduces one

proposition from another, or proceeds from proposition from another, or proceeds from premises to consequences.”premises to consequences.”

– ““Ratiocination; discursive power.”Ratiocination; discursive power.”

The same two terms are used for contrast The same two terms are used for contrast when defining “intuition” and “intuitive”.when defining “intuition” and “intuitive”.

3838

3939

Hume’s UsageHume’s Usage

Hume, like Johnson, refers to “deductions” Hume, like Johnson, refers to “deductions” and “ratiocination” in contexts where and “ratiocination” in contexts where stepwise argument is clearly intended:stepwise argument is clearly intended:– TT 1.3.14.2, 1.3.14.2, E E 5.22, 5.22, M M 1.4; 1.4; EE 4.23, 4.23, E E 12.1712.17

He also refers to “arguments” “inference” He also refers to “arguments” “inference” and “proof” that are “intuitive”:and “proof” that are “intuitive”:– TT 1.3.14.35, 1.3.14.35, TT 2.3.2.2, 2.3.2.2, EE 4.21, 4.21, EE 8.22 n. 18 8.22 n. 18

Hume’s own theory of inductive “reasoning” Hume’s own theory of inductive “reasoning” implies that it is not typically stepwise!implies that it is not typically stepwise!

3939

4040

Hume’s Conclusion (Garrett 1997)Hume’s Conclusion (Garrett 1997)

““Hume . . . [is] making a specific claim, within Hume . . . [is] making a specific claim, within cognitive psychology, about the relation between cognitive psychology, about the relation between our tendency to make inductive inferences and our our tendency to make inductive inferences and our inferential/argumentative faculty: he is arguing that inferential/argumentative faculty: he is arguing that we do not adopt induction on the basis of we do not adopt induction on the basis of recognising an recognising an argumentargument for its reliability … this for its reliability … this does not mean that inductive inferences are not does not mean that inductive inferences are not themselves themselves instances instances of argumentation or of argumentation or reasoning; … His point is rather that they are reasoning; … His point is rather that they are reasonings that are not themselves produced by reasonings that are not themselves produced by any piece of higher level reasoning” (pp. 91-2)any piece of higher level reasoning” (pp. 91-2)

4040

4141

What About Intuition?What About Intuition?

One objection to Garrett’s position (Millican One objection to Garrett’s position (Millican 1998, p. 151) is that in the 1998, p. 151) is that in the EnquiryEnquiry, Hume , Hume also rules out also rules out intuitionintuition (which is not (which is not reason-reason-inging in in GarrettGarrett’s sense) as the basis of UP.’s sense) as the basis of UP.

He responded in our He responded in our Hume StudiesHume Studies debate: debate:““Hume … in the Hume … in the EnquiryEnquiry … expands the famous … expands the famous conclusion to rule out any ‘reasoning conclusion to rule out any ‘reasoning or process or process of the understandingof the understanding,’ thereby eliminating such ,’ thereby eliminating such non-inferential processes of the understanding non-inferential processes of the understanding as intuition …” (1998, p. 184)as intuition …” (1998, p. 184)

4141

42424242

Reason = The UnderstandingReason = The Understanding

But Hume implicitly identifies But Hume implicitly identifies reasonreason with with the understandingthe understanding in many places, e.g.: in many places, e.g.:

““When the mind [makes an inductive inference] it When the mind [makes an inductive inference] it is not determin’d by is not determin’d by reasonreason, but by certain , but by certain principles, which associate together the ideas of principles, which associate together the ideas of these objects, and unite them in these objects, and unite them in the imaginationthe imagination. . Had ideas no more union in Had ideas no more union in the fancythe fancy than than objects seem to have to objects seem to have to the understandingthe understanding, …”, …” ( (T 1.3.6.12T 1.3.6.12))

– See also See also TT 1.3.6.4, 1.4.1.1, 1.4.2.46, 1.4.2.57, 1.3.6.4, 1.4.1.1, 1.4.2.46, 1.4.2.57, 1.4.7.7, and compare 2.2.7.6 n. with 1.3.9.19 n.1.4.7.7, and compare 2.2.7.6 n. with 1.3.9.19 n.

4343

A Sign of Convergence… ?A Sign of Convergence… ?

Garrett has now acknowledged that Hume Garrett has now acknowledged that Hume equates “reason” and “the understanding”:equates “reason” and “the understanding”:

““I grant that Hume roughly interchanges the terms I grant that Hume roughly interchanges the terms ‘reason’ and ‘understanding’ … The understanding ‘reason’ and ‘understanding’ … The understanding generally involves the intuition of self-evident truths generally involves the intuition of self-evident truths as well as reasoning … Peter thinks reason for as well as reasoning … Peter thinks reason for Hume Hume blew upblew up to cover everything that the Lockean to cover everything that the Lockean understanding did, while I think that in Hume the understanding did, while I think that in Hume the understanding shrank down to encompass only understanding shrank down to encompass only what reason did, plus intuition.” (2011, pp. 18-19)what reason did, plus intuition.” (2011, pp. 18-19)

To me, this shrinking is historically implausible.To me, this shrinking is historically implausible.4343

4444

Epistemology or Cognitive Science?Epistemology or Cognitive Science?

Garrett’s 1997 formulation has a tension:Garrett’s 1997 formulation has a tension:– He sees the argument as He sees the argument as cognitive psychologycognitive psychology

rather than rather than epistemologyepistemology: concerning the : concerning the mechanismmechanism of inductive inference rather than of inductive inference rather than whether or not it can be whether or not it can be justifiedjustified..

– Yet he takes Hume’s conclusion to be thatYet he takes Hume’s conclusion to be that“we do not adopt induction on the basis of “we do not adopt induction on the basis of recognising recognising an argument for its reliabilityan argument for its reliability, for , for … there … there isis no argument … that could have this no argument … that could have this effect. … we can literally ‘give no reason’ for effect. … we can literally ‘give no reason’ for our making inductive inferences” (1997, p. 92).our making inductive inferences” (1997, p. 92).

4444

4545

Hume’s Conclusion (Garrett 2002)Hume’s Conclusion (Garrett 2002)

““Hume … [is] making a specific claim, within Hume … [is] making a specific claim, within cognitive psychology, about the underlying cognitive psychology, about the underlying causal mechanism that gives rise to inductive causal mechanism that gives rise to inductive inference: namely, that it is not itself dependent inference: namely, that it is not itself dependent on any reasoning or inference. … this does not on any reasoning or inference. … this does not mean that inductive inferences are not mean that inductive inferences are not themselves themselves instances instances of argumentation or of argumentation or reasoning; … His point is rather that they are reasoning; … His point is rather that they are reasonings which are not themselves reasonings which are not themselves causedcaused by by any piece of reasoning (including, of course, any piece of reasoning (including, of course, themselves). themselves). ” (p. 333)” (p. 333)

4545

4646

HeHe also made an important clarification: also made an important clarification:““Millican understandably infers that on my Millican understandably infers that on my interpretation ‘it is only the interpretation ‘it is only the general practicegeneral practice of of induction that fails to be determined by reason, induction that fails to be determined by reason, and each of our and each of our particularparticular inductive inferences inductive inferences is itself an instance of the operation of our is itself an instance of the operation of our reason.’ … The crucial distinction for Hume, reason.’ … The crucial distinction for Hume, however, is … between an inference being an however, is … between an inference being an instanceinstance of reasoning and the same inference of reasoning and the same inference being being caused bycaused by (another instance of) (another instance of) reasoning.” (1998, pp. 180-1)reasoning.” (1998, pp. 180-1)

4646

Induction in General, or Individual?Induction in General, or Individual?

4747

The Inheritance ProblemThe Inheritance Problem

Here the problem for Garrett is to give a Here the problem for Garrett is to give a plausible precise account of Hume’s claim.plausible precise account of Hume’s claim.

If the claim concerns every individual If the claim concerns every individual inductive inference, and is a claim about the inductive inference, and is a claim about the psychological mechanismpsychological mechanism involved in such involved in such inference (rather than about inference (rather than about epistemological epistemological foundation), then it is unclear why lack of foundation), then it is unclear why lack of ratiocinative causationratiocinative causation should be “inherited” should be “inherited” by a by a laterlater argument that starts from a argument that starts from a previously-taken-as-established previously-taken-as-established lemmalemma..

4747

48484848

FO(c,e)

FO(p,u)

¬FO(p,R)

FO(e,u)

¬FO(u,s)

¬FO(u,d)

¬FO(u,R)¬FO(u,i)

¬FO(u,p)

FO(p,c)

FO(p,e)

An Objection from the An Objection from the Logic of Hume’s Logic of Hume’s

ArgumentArgument

Consider this Consider this final stepfinal step

49494949

An Implausible Non-SequiturAn Implausible Non-Sequitur

The final step of Hume’s argument makes The final step of Hume’s argument makes no sense on Garrett’s interpretation:no sense on Garrett’s interpretation:– UP plays a role in the causation of probable UP plays a role in the causation of probable

inference; inference;

– UP is not itself caused by a process of ratiocination;UP is not itself caused by a process of ratiocination;

– Therefore probable inference is not caused by any Therefore probable inference is not caused by any process of ratiocination.process of ratiocination.

This is a complete This is a complete non-sequiturnon-sequitur. Probable . Probable inference could be caused by a process of inference could be caused by a process of ratiocination that involves UP!ratiocination that involves UP!

50505050

Further Logical ObjectionsFurther Logical Objections

If Hume were only concerned to prove that If Hume were only concerned to prove that ratiocinationratiocination plays no role in the plays no role in the causationcausation of induction (i.e. probable inference), then:of induction (i.e. probable inference), then:– His argument would be incomplete, because His argument would be incomplete, because

he does nothing to rule out the possibility that he does nothing to rule out the possibility that induction could be caused by induction could be caused by badbad argument. argument.

– Much of his Much of his EnquiryEnquiry argument would be argument would be redundant, because he would have no need to redundant, because he would have no need to refute the idea that induction is founded on refute the idea that induction is founded on intuition or sensation.intuition or sensation.

5151

Arguments Can Be Bad!Arguments Can Be Bad!

Hume quite often refers to arguments that Hume quite often refers to arguments that are fallacious, for example:are fallacious, for example:– ““can any thing be imagin’d more absurd and can any thing be imagin’d more absurd and

contradictory than this reasoning?” (contradictory than this reasoning?” (T T 1.2.4.11)1.2.4.11)– ““Few have been able to withstand the seeming Few have been able to withstand the seeming

evidence of this argument; and yet nothing … is evidence of this argument; and yet nothing … is more easy than to refute it.” (more easy than to refute it.” (T T 1.4.5.30)1.4.5.30)

– ““I shall not leave it to Philo … to point out the I shall not leave it to Philo … to point out the weakness of this metaphysical reasoning. … I weakness of this metaphysical reasoning. … I shall myself … show the fallacy of it.” (shall myself … show the fallacy of it.” (DD 9.4) 9.4)

5151

5252

Induction from the Causal MaximInduction from the Causal Maxim

Hume refutes various attempted demonstr-Hume refutes various attempted demonstr-ations of the Causal Maxim, at ations of the Causal Maxim, at TT 1.3.3.4-8. 1.3.3.4-8.

But such a would-be demonstration could But such a would-be demonstration could very naturally be used to support induction, very naturally be used to support induction, on the ground that if every change must on the ground that if every change must have a cause, then the have a cause, then the ultimateultimate causal laws causal laws must be consistent over time.must be consistent over time.

It is hard to see how Garrett’s interpretation It is hard to see how Garrett’s interpretation of Hume’s argument can rule this out.of Hume’s argument can rule this out.

5252

5353

Price on the Causal Maxim and InductionPrice on the Causal Maxim and Induction

Richard Price, in Richard Price, in A Review of the Principal A Review of the Principal Questions in MoralsQuestions in Morals (1758), argued like (1758), argued like this, taking the Causal Maxim as intuitive:this, taking the Causal Maxim as intuitive:

““The conviction produced by experience is built on The conviction produced by experience is built on the same principle … Because we see intuitively, the same principle … Because we see intuitively, that there being some reason or cause of this that there being some reason or cause of this constancy of eventconstancy of event, it must be derived from , it must be derived from causes regularly and constantly operating … And causes regularly and constantly operating … And the more frequently and uninterruptedly we knew the more frequently and uninterruptedly we knew this had happened, the stronger would be our this had happened, the stronger would be our expectation of its happening again” (p. 40 n.)expectation of its happening again” (p. 40 n.)

5353

54545454

““Reason is …”Reason is …”

““Reason is the discovery of truth or falshood.” Reason is the discovery of truth or falshood.” ((TT 3.1.1.9) 3.1.1.9)

““That Faculty, by which we discern Truth and That Faculty, by which we discern Truth and Falshood … the Understanding”Falshood … the Understanding”(E(E 1.14, note in 1748/1750 editions 1.14, note in 1748/1750 editions))

“… “… reason, in a strict sense, as meaning the reason, in a strict sense, as meaning the judgment of truth and falsehood …” (judgment of truth and falsehood …” (DOPDOP 5.1) 5.1)

See also See also TT 2.3.3.3, 2.3.3.5‑6, 2.3.3.8, 2.3.10.6,  2.3.3.3, 2.3.3.5‑6, 2.3.3.8, 2.3.10.6, 3.1.1.4, 3.1.1.19 n. 69, 3.1.1.25‑27, 3.2.2.20, 3.1.1.4, 3.1.1.19 n. 69, 3.1.1.25‑27, 3.2.2.20, MM 1.7,  1.7, M AppM App 1.6, 1.21. 1.6, 1.21.

55555555

““Reason” as Our Cognitive FacultyReason” as Our Cognitive Faculty

We should take Hume at his word: by We should take Hume at his word: by “reason” he means our cognitive powers – “reason” he means our cognitive powers – our discernment or discovery of what is the our discernment or discovery of what is the case, truth or falsehood.case, truth or falsehood.

These powers are generally taken to include These powers are generally taken to include memory, sensation, intuition, demonstration, memory, sensation, intuition, demonstration, and probable inference.and probable inference.

Hume shows that none of these can provide Hume shows that none of these can provide a basis for claiming to discern the ongoing a basis for claiming to discern the ongoing truth of the Uniformity Principle.truth of the Uniformity Principle.

56565656

Induction as Part of Reason …Induction as Part of Reason …

On this interpretation, induction On this interpretation, induction remainsremains includedincluded amongst the operations of reason, amongst the operations of reason, even after Hume has famously concluded that even after Hume has famously concluded that it is “not founded on reason”.it is “not founded on reason”.

This rejects the view of Beauchamp, Winters, This rejects the view of Beauchamp, Winters, Baier, Millican (1995) and Owen (etc.) that Baier, Millican (1995) and Owen (etc.) that Hume’s “reason” is ambiguous, switching to a Hume’s “reason” is ambiguous, switching to a less demanding notion following less demanding notion following TT 1.3.6. 1.3.6.

It agrees with Garrett in rejecting any crude It agrees with Garrett in rejecting any crude ambiguity (but on a different basis).ambiguity (but on a different basis).

57575757

… … But Not “Founded on Reason”But Not “Founded on Reason”

How, then, can induction be How, then, can induction be part ofpart of reason but reason but yet “not yet “not foundedfounded on reason”? on reason”?

What Hume seems to be doing in the case of What Hume seems to be doing in the case of induction, the external world, and morality is induction, the external world, and morality is performing a deep analysis of what the relevant performing a deep analysis of what the relevant human power involves – identifying the human power involves – identifying the conceptual steps that are implicit in its activity – conceptual steps that are implicit in its activity – and then using faculty language (“founded on and then using faculty language (“founded on reason”, “founded on the imagination” etc.) to reason”, “founded on the imagination” etc.) to express those underlying stepsexpress those underlying steps..

58585858

A Crucial Step …A Crucial Step …

In performing such analysis, Hume focuses In performing such analysis, Hume focuses on one particularly vital step or weak link:on one particularly vital step or weak link:– When investigating induction, he focuses on When investigating induction, he focuses on

the crucial step of extrapolation from observed the crucial step of extrapolation from observed to unobserved which, in effect, supposes a to unobserved which, in effect, supposes a Uniformity Principle between them.Uniformity Principle between them.

– In the case of the external world, he focuses on In the case of the external world, he focuses on the crucial step that takes us from interrupted the crucial step that takes us from interrupted sense impressions to our “assurance of the sense impressions to our “assurance of the continu’d and distinct existence of body”continu’d and distinct existence of body”..

59595959

… … Which is “Imagination-Like”Which is “Imagination-Like”

When the underlying step turns out to be When the underlying step turns out to be “imagination-like” – involving processes such “imagination-like” – involving processes such as the as the communication of vivacity through communication of vivacity through associationassociation or the or the creation of “fictions”creation of “fictions” (or, (or, least respectably, the least respectably, the operation of “whimsies operation of “whimsies and prejudices”and prejudices”) – Hume describes that step ) – Hume describes that step as owing to “the imagination”, as owing to “the imagination”, even if the step even if the step concerned is located, within our cognitive concerned is located, within our cognitive economy, as part of the operation of our economy, as part of the operation of our reasoning or our sensesreasoning or our senses..

60606060

Reason and the ImaginationReason and the Imagination

Thus the conclusion of Hume’s famous Thus the conclusion of Hume’s famous argument concerning induction comes to argument concerning induction comes to something like this:something like this:

Our cognitive process of inductive inference Our cognitive process of inductive inference crucially depends on a sub-process which is crucially depends on a sub-process which is imagination-likeimagination-like (based on associative (based on associative extrapolation) rather than extrapolation) rather than reason-likereason-like (based (based on apprehension of what is the case).on apprehension of what is the case).

Note that this does not prevent induction’s Note that this does not prevent induction’s retaining its status as a part of our reason. retaining its status as a part of our reason.