June 15, 2012
Ok, so what does all this amount to? Well, in very brief:
– Reliabilism is an attempt to give an objective account of what it is to be entitled to a belief, independent of anyone’s judgements of entitlement.
– Reliabilism therefore aims to sever entitlement from judgements of entitlement.
– Brandom shows that the criteria of entitlement that reliabilism attempts to supply, cannot be made sense of except in terms of a given reference-frame or normative perspective.
– Brandom therefore shows that reliabilism cannot sever entitlement from normative reference frames, as it purports to.
– Brandom (independently) argues that these normative reference frames should be understood in social-perspectival terms.
– If Brandom is right about the last point, this means that reliabilism cannot provide a counter-position to Brandom’s social account of knowledge.
Very good. But what about non-social-perspectival accounts of normative reference frames? Let’s grant that we need *some* normative reference frame for ‘reliability’ to be specified in a way that can get a broadly reliabilist account of entitlement off the ground. Why should this normative framework be *social*?
Brandom’s fundamental answer to this question is simply the unfolding of his system. As Brandom puts it in the Preface to Making It Explicit:
The idea is to show what kind of understanding and explanatory power one gets from talking this way, rather than to argue that one is somehow rationally obliged to talk this way. (xii)
In other words, Brandom does not aspire to a knock-down argument against all alternative systems – he simply aims to show some of the things his own model can do, and make a case for its utility and plausibility on those grounds. Nevertheless, it can be worthwhile looking at rival positions, to get a sense of why Brandom’s system might be an attractive one.
My plan for the next set of posts in this series on Brandom is roughly as follows:
– Next, I will outline a popular alternative account of the origin of norms (including the normative frameworks that can help specify the nature of a given ‘reliability’) – this is the approach, grounded in evolutionary biology, that is often called ‘teleosemantics’.
– Then I will try to explain why teleosemantics is a theoretical and explanatory dead-end. (Thereby suggesting some of the benefits of Brandom’s alternative social-perspectival approach).
– I will then contextualise Brandom’s social-perspectival approach as an inheritor of the much more famous (and reviled) (and problematic) social-perspectival approach articulated by Richard Rorty, in his Philosophy and the Mirror of Nature, and later works.
– I will then argue that Brandom’s system can be seen as an attempt to ‘realise’ Rorty’s project. I will claim that this in my opinion successful ‘realisation’ also transforms Rorty’s project in a manner that removes Rorty’s tacit idealism.
– I’m probably going to have to discuss Sellars somewhere, in amongst that lot.
This will hopefully set us up to give a more thorough account of Brandom’s account of normative and referential objectivity. Once I’ve developed that adequately, I can finally turn to some of the social-theoretic implications of Brandom’s apparatus.
That’s the plan anyway. We’ll see how it goes. (Posting will remain very infrequent.)
June 3, 2012
I’ve been saying that Brandom contrasts his own position w/r/t perceptual knowledge with a ‘reliabilist’ one. What does ‘reliabilism’ consist in?
All the theories of perceptual knowledge in contention in this theoretical space agree that for something to be knowledge it must be:
a) a belief
All the theories in contention furthermore agree that not all true beliefs are knowledge: an additional criterion or criteria are required in order to distinguish knowledge from the larger class of true beliefs.
The classic additional criterion to distinguish knowledge from true belief is justification: on this account, something is knowledge if it is justified true belief. But, notoriously, it is difficult to give an account of what such justification can consist in that gives results compatible with our intuitions as to what does and does not count as knowledge.
Raymond Gettier’s classic article ‘Is Justified True Belief Knowledge?’ poses a series of dilemmas for the straightforward ‘justified true belief’ position –these dilemmas have been extended and added to by subsequent philosophers. [An example of a relatively simple ‘Gettier problem’: let’s say I put ten coins in my pocket this morning; later in the day, five coins fall out of my pocket; still later in the day, a kindly sprite places five more coins in my pocket; I now believe, correctly, that there are ten coins in my pocket, and I am justified in that belief, because I remember putting ten coins in my pocket earlier, but can I really be said to know that there are ten coins in my pocket, given the actual reasons why there are ten coins there, which are not at all the ones I imagine? These sorts of examples are always enormously silly and tedious; I’ll try to keep them to a minimum in the remainder of the discussion; I promise we’re headed places that have more bearing on things that people actually sometimes care about.] Much subsequent work within analytic philosophy has focused on ways in which the ‘justified’ criterion can be made more complicated and sophisticated to take account of such ‘Gettier’ problems.
One obvious issue with the ‘justified’ criterion, is whether the possessor of knowledge needs themselves to be conscious or aware of the justification for their true beliefs, in order for those beliefs to be justified. If we decide that the believer must themselves be aware of the justification for their belief, we seem (at least potentially) to be vulnerable to an infinite regress of the ‘KKp’ type. That is, if we must know the basis for our knowledge, then it seems we must also know the basis for that knowledge of our knowledge’s basis, and so on. This looks to be a vicious infinite regress – which in turn implies that at some point we need to bottom out w/r/t knowledge (or even belief concerning basis of knowledge) – another version of the ‘regulism’ problem I have already discussed on the blog.
If we assume, then, that we do not necessarily need to know why our knowledge is justified, in order for it to be justified, we seem to open the nature of justification to being something extra-psychical or -meaningful – something outside the ambit of consciousness or of social practice. A series of post-Gettier accounts of knowledge aim to cash out the ‘justification’ criterion in terms of the causal mechanisms that connect knowledge claims and the objects of those knowledge claims. For example, Alvin Goldman’s 1967 ‘A Causal Theory of Knowing’ argued that the missing justification-criterion was an appropriate causal connection between the object of the knowledge-claim and the knowledge-claim itself (potentially regardless of how the knowledge-claimer themselves understand that causal chain).
There are various problems with a straightforward causal theory of knowledge. One of them is that we can imagine or construct scenarios that involve exactly the same causal mechanism connecting a knowledge-claim and the object of knowledge, where it seems that some of these scenarios genuinely produce knowledge, but others do not.
An example here, much beloved of Brandom, is the ‘Barn Façade County’ thought experiment. [I think the origin of this is Goldman’s 1976 ‘Discrimination and Perceptual Knowledge’, though it’s obviously been extended since that paper, and I’m not sufficiently abreast of the literature to be able to track the thought experiment’s progress.] In this thought experiment a perceiver (call him, following Goldman, Henry) perceives what appears to him to be a barn. Unbeknownst to Henry, however, he is presently in Barn Façade County – a district the favourite pastime of whose inhabitants is constructing incredibly realistic facades of barn-fronts. [Sorry again about the moronic analytic philosophy thought experiments.] Here it seems unreasonable to say that Henry knows that there is barn in front of him. Nevertheless, it also seems unreasonable to say that in most other circumstances Henry is unable to know about the existence of a barn, because it is always possible that he be in Barn Façade County or some similarly idiosyncratically deceptive environment.
The problem here is a version of a general skeptical problem. It is always possible that we be mistaken about any given claim – but we don’t want to conclude, because of this, that we can never have knowledge of anything.
The epistemological theory – a version of the causal theory of knowing – that many philosophers adopt in order to give a non KKp-vulnerable account of the basis of justification, is that a person knows P if they believe P, P is true, and the person is generally a reliable reporter of P. This is ‘reliabilism’.
Brandom does not dispute the claims in the previous paragraph. But he disputes that they are enough to give us an account of justification.
Returning again to the Barn Façade County example, Henry can be a generally reliable reporter of the presence of barns (in almost all counties), and an extremely unreliable reporter of the presence of barns within Barn Façade County. Whether or not Henry is a reliable reporter of the presence of barns is relative to the environment in a way that does not impact on the causal connection between the object of Henry’s knowledge and his knowledge claims.
Reliablist theories of knowledge try to take this problem into account. As Goldman puts it in his 1976 paper:
A person knows that p, I suggest, only if the actual state of affairs in which p is true is distinguishable or discriminable by him from a relevant possible state of affairs in which p is false… The qualifier ‘relevant’ plays an important role in my view. If knowledge required the elimination of all logically possible alternatives, there would be no knowledge (at least of contingent truths). If only relevant alternatives need to be precluded, however, the scope of knowledge could be substantial. (p. 773-4)
Superficially, this class of positions appears to give us a definition of justification which is wholly separable from the social practice of taking-as-justified. On the reliabilist account, a person is justified in believing p if they reliably believe p when p, and not-p when not-p, in relevant scenarios. Whether or not the person exhibits this reliable responsive relationship to an objective fact about the world seems itself to be an objective fact about the world – it is not dependent on (narrowly understood) social acts of taking-as (other than the belief that p or not-p itself, and whatever mechanisms led to that belief-formation).
And in a sense this is true. But the devil is in the detail – or, more precisely, in the concept of ‘relevance’. Relevance cannot be objectively defined. Whether or not a scenario is ‘relevant’ is not a bare fact about the physical make-up of the world. To take a scenario to be relevant is to take it to be relevant. This means that the reliablist account must be folded back into an account of social (or at least normative) acts of taking-as.
As Brandom puts it, in relation to the ‘Barn Façade County’ example:
Goldman’s idea is that reliability is an objective affair, determined by the objective probability of a correct judgment, given one’s circumstances. But such probabilities vary with the specification of those circumstances. Given a reference class of relevantly similar cases, frequencies of success define objective probabilities. The question remains how a privileged reference class is to be determined. What is the correct reference class with respect to which to assess such probabilities?
Focusing on the relativity of reliability to decisions about where to draw these boundaries makes it evident that the question “Reliable or not?” is underdetermined in exactly the same way that the question “Regular or not?” is underdetermined. There are always some regularities that are being instantiated, and (in the case where the claim one is making is true) there are always some reference classes with respect to which one is reliable. Using these naturalistic notions to stand in for genuinely normative assessments works only relative to some way of privileging regularities or reference classes. (MIE p. 211)
This privileging of reference classes – which provide the framework within which naturalistic judgements of reliability can be made – is itself a normative practice; which means, if Brandom’s apparatus is correct, a social practice. Causal and reliabilist theories of knowledge, therefore throw us back onto social processes.
It is worth noting, in passing, that this provides another example of the (virtuous) circularity of Brandom’s own apparatus. Brandom too, of course, relies upon the concept of reliability to play a foundational explanatory role: Brandom’s entire apparatus is built up out of reliable differential responsive dispositions. Yet Brandom is clear that what constitutes reliability can only be judged from within a normative (social) framework that provides reference classes from within which reliability can be assessed. RDRDs provide the foundation for Brandom’s apparatus, therefore – but to discuss RDRDs at all requires a social framework generated by those RDRDs, in their complex interaction. This is true for many reasons – but the necessity of normatively determined reference classes for the analysis of reliability is one such reason.
May 13, 2012
A helpful way to approach Brandom’s inferentialism is to look at some of the positions he takes it to oppose. In this post I will begin to discuss one such position, which Brandom labels ‘reliabilism’.
Recall that the opposition here is between positions that take representation or reference to be explanatorily primitive within semantics, and Brandom’s own position, which argues that representation or reference can be fully explained in terms of inference. For Brandom, inference is a social thing – the language-behaviours with which we attribute and endorse inferences are social behaviours. Reference, by contrast, very much appears to involve something other than social practice – indeed, it is hard to imagine a credible account of reference that does not involve entities and events that would not ordinarily be categorised as social. If I state that the surface temperature of the planet Mercury can reach 700 degrees Kelvin, and that by around 8 billion years from now, by our best estimates, that planet, along perhaps with Earth, will have been destroyed by the expansion of the sun to around 256 times its present radius, I am making claims about entities that do not, in any very narrow sense, participate in our social practices. Neither are the causal mechanisms by which these entities (Mercury; the sun) impact upon our senses and equipment, mechanisms that would ordinarily be called ‘social’
Nevertheless, Brandom believes that representation should be understood in social terms. What does this mean?
We can start to unpack this by contrasting Brandom’s position with a common alternative account of reference, which Brandom (following standard philosophical usage) labels ‘reliabilism’. The issue here, of course, is how we gain empirical knowledge of the world – we are interested for now in language-entry moves (perception), rather than language-exit moves (action).
Recall, then, that Brandom’s account is built up out of reliable differential responsive dispositions (RDRDs). RDRDs are the basic (if you like ‘ontological’) building blocks of Brandom’s account. [Though this is a ‘weak’ rather than a ‘strong’ ontology, in that it does not make any claims about the ‘fundamental’ entities that inhabit our world; merely the kinds of behaviour some entities in our world must be capable of exhibiting if our account is to have any explanatory function.] Given this, it would seem to make sense for Brandom’s system to take reliability of responsiveness to stimuli as the core of its account of representation.
Brandom frames his discussion of reliabilism in relation to the classic definition of knowledge as justified true belief. In his seminal “Is Justified True Belief Knowledge?” Edmund Gettier attributes this position to A.J.Ayer, Roderick M. Chisholm, and, more tentatively, Plato. I need, obviously, to do a more thorough review of the literature here…
A central question for justified true belief accounts of knowledge, is what constitutes justification. Brandom’s overall strategy, in keeping with his normative phenomenalism, is to explain justification in terms of the social practices of taking-as-justified. (Similarly, Brandom will explain truth in terms of taking-true; and he will explain the content of belief – that which makes a belief a belief about something, and thus a belief at all – in terms of the inferential practices of attributing and acknowledging commitments. This is all, for now, a separate set of issues.)
However, the justification of our beliefs does not prima facie have to be accounted for in terms of the activity of justifying them. As Brandom puts it:
It is generally agreed that some sort of entitlement to a claim is required for it to be a candidate for expressing knowledge. But it is not obvious that inferring in the sense of justifying is at all fundamental to that sort of entitlement.
The core point, it appears, is that our beliefs cannot be accidental if they are to be capable of counting as justified. A belief formed by flipping a coin will not (unless, perhaps, we attribute the coin-flip’s outcome to the intervention of a supernatural power) provide justified belief even if (by chance) it provides true belief. An account is needed of the non-fortuitous formation of a belief if it is to be a candidate for knowledge.
‘Reliabilism’ does exactly this, without invoking inferential justification. In Brandom’s words:
[T]he correctness of the belief is not merely fortuitous if it is the outcome of a generally reliable belief-forming mechanism. Epistemological reliabilists claim that this is the sort of entitlement status that must be attributed (besides the status of being a true belief) for attributions of knowledge.
Brandom makes use of Alvin Goldman’s ‘Barn Facade County’ thought experiment (from Goldman’s “Discrimination and Perceptual Knowledge”, Journal of Philosophy 73, no. 20 (1976)) to argue against the reliabilist position. I’ll talk about this next.
May 12, 2012
Brandom’s system is an ‘inferentialist’ one. Brandom frames much of his work by contrasting this ‘inferentialism’ with what he calls ‘representationalism’. These are two different approaches to understanding conceptual content. ‘Representationalism’ is the view that representation should be taken as explanatorily fundamental for semantics. On this picture, certain linguistic units have meanings by virtue of their powers to denote, or refer. These units can then be connected and combined in propositional structures or belief-webs, the subsections of which can be connected by chains of inference. This is the picture of language proposed by Bertrand Russell, and by the early analytic philosophers working within the logistic paradigm Russell popularised within the English-language discipline. There are simple units of reference, which can be combined and manipulated by using fundamental logical tools of inference. Inference is explanatorily basic, also, on this account – inference cannot be explained in terms of reference. But reference likewise cannot be explained in terms of other semantic concepts.
‘Inferentialism’, by contrast, takes inference as explanatorily fundamental. Furthermore – and seemingly implausibly – it suggests that representation can be explained in terms of inference. On this inferentialist picture, inferences do not connect independently-comprehensible representational content-units. Representations can only be understood – and can be fully explained – as products of inferences.
In Making It Explicit (and in other works) Brandom distinguishes between three kinds of inferentialism: weak inferentialism, strong inferentialism, and hyper-inferentialism. Brandom himself endorses ‘strong inferentialism’. Here are his characterisations of the positions (from Articulating Reasons, p. 219-220):
Weak inferentialism is the claim that inferential articulation is a necessary aspect of conceptual content. Strong inferentialism is the claim that broadly inferential articulation is sufficient to determine conceptual content (including its referential dimension). Hyperinferentialism is the claim that narrowly inferential content is sufficient to determine conceptual content.
Obviously the key here is the difference between “broadly” and “narrowly” inferential content. Brandom characterises the difference as follows:
Broadly inferential articulation is sufficient to determine conceptual content. Broadly inferential articulation includes as inferential the relation even between circumstances and consequences of application, even when one or the other is noninferential (as with observable and immediately practical concepts), since in applying any concept one implicitly endorses the propriety of the inference from its circumstances to its consequences of application. Narrowly inferential articulation is restricted to what Sellars calls “language-language” moves, that is, to the relation between propositional contents.
Brandom presents here a ‘web of belief’ picture, in which propositional contents are related inferentially. Proposition A implies proposition B, and both are incompatible with proposition C, etc. If we understand propositional contents in linguistic terms – propositions being things that can be expressed in sentences – then we can think of the inferential relationships between propositions as relationships between specific linguistic contents. An inference is a “language-language” move, in that it connects one linguistic content to another linguistic content.
Hyperinferentialism, as Brandom characterises it, suggests that linguistic content can be fully understood in terms of these language-language moves. This has some similarities to the class of positions discussed by John McDowell (in his Mind and World) under the heading of ‘coherentism’ (McDowell’s particular target in these discussions is Donald Davidson). The objection to this position is that it seems to sever conceptual content from any connection to the outside world (or, more properly, any rational connection – any connection that can rightly be taken as placing a warranted constraint or having a justificatory bearing on the content of our propositions). In McDowell’s words, this picture:
depicts our empirical thinking as engaged in with no rational constraint, but only causal influence, from outside… Coherentist rhetoric suggests images of confinement within the sphere of thinking, as opposed to being in touch with something outside it.
Brandom too regards this as the likely penalty of a hyperinferentialist understanding of conceptual content. Such an understanding, Brandom claims, may be plausible “at most for some abstract mathematical concepts” (AR, p. 220). It is, however, an inadequate explanatory apparatus if we aspire to treat the empirical richness of most conceptual content.
Weak inferentialism, by contrast, suggests that while inferential connections between propositional contents are a necessary component of our explanation of conceptual content (a concept cannot have content if nothing follows from that content), an account of inference cannot be sufficient to fully explain conceptual content: some other category – i.e. reference – must be brought in to account for the (rational) connection between words (or propositional contents) and things.
What is the nature of the ‘strong inferentialism’ Brandom advocates, which aims to chart a course between these two alternatives? Another way of putting this: what is the category of ‘broad inference’ that encompasses more than simply language-language moves under the heading of inference, for Brandom?
The important Chapter 4 of Making It Explicit addresses these issues. There Brandom discusses ‘Perception and Action’ – or, as he also terms then, ‘language-entry’ and ‘language-exit’ moves. Language-entry moves (perceptions) allow things outside of linguistic practice (the regular furniture of our world) to impinge upon, influence, generate and destroy the conceptual contents we manipulate in our thoughts and statements – to have a bearing upon which conceptual contents are warranted, and which are not. Language-exit moves, by contrast, allow our concepts to impact upon the world in more thoroughgoing ways than via the usual articulation of sentences or interaction of brain-behaviours – we act and transform the world in ways that are connected to our beliefs, and the justification or otherwise of these actions is connected to the content of those beliefs.
How can these perceptions and actions be folded within an ‘inferentialist’ account of conceptual content? In what sense should the perception of a moving rock, or the action of kicking one, be understood ‘inferentially’?
February 8, 2012
The next important building block of Brandom’s inferentialism is his analysis of deontic status in terms of deontic attitudes – but I’ve sort of already covered that in broad brush strokes, last year on the blog.
Also worth mentioning the priority of judgements in Brandom’s account of meaning: Brandom does not understand judgements in terms of their composition out of smaller meaning-units, but understands smaller meaning-units in terms of the roles they play in judgements. (And of course a judgement, for Brandom, can only be a judgement as part of a larger social system of judgements.)
So those are two further explanatory approaches that Brandom’s project is committed to. I’m not going to spend much time on them here.
In addition, though, for Brandom [and here we start to move into territory I’ve not covered already on the blog; if you see something you regard as a mistaken interpretation, please feel free to flag it as such] we become concept-mongers by entering the space of reasons; by participating in the social practice of asking for and giving reasons.
This is Brandom mobilising Sellars. I’ve read Empiricism and the Philosophy of Mind – I’m not totally clear what other Sellars I should look at to get an adequate sense of the resources Brandom’s making use of / transforming. Recommendations would be welcome.
What is the explanatory order here?
Brandom thinks that concepts need to be understood in inferential terms. That is, roughly – the meaning of a concept is the things we can infer from it. To be very slightly more precise: concepts can for Brandom only be understood in relation to judgements. A judgement is something that can be expressed in a proposition. So the concept of a dog, for example, needs to be understood in terms of the role the concept of a dog plays in propositions about dogs. Sticking at the propositional level, then – a proposition needs to be understood in terms of the inferences we can make from it. Or, to be very slightly more precise still: “Two claims have the same conceptual content if and only if they have the same inferential role.” (MIE 96)
What is an inferential role? Brandom understands inferential role in terms of deontic statuses – which, as we’ve already seen, he in turn understands in terms of deontic attitudes. There are, I think, two fundamental deontic statuses in Brandom’s account: commitment and entitlement. I’ll need to spend a lot longer with these in future posts. But Brandom’s basic idea is that an assertion of a proposition binds one to certain actions (including the endorsement of other propositions), normatively. Those other actions – including those other propositional contents – follow from the assertion – they can be inferred from it – and this binding or inference is itself the content of the original proposition. The meaning of a judgement is that other judgements or actions are implied by it. Content is explained in terms of implications, rather than implications in terms of content.
Where does this binding or this implication come from? What is it?
Brandom’s claim here, if I understand him aright, is that the brute fact that we are animals who ask for and give reasons is the source of the bindingness of commitments etc. – and thus of normativity. That means we are creatures who ask each other for demonstrations of entitlement. This is a brute fact about us. And the content of an entitlement – indeed, the very nature of entitlement itself – needs to be understood in terms of this social practice of challenge and response.
We are creatures who, discursively, ask each other for reasons – that is, challenge social entitlement – and who feel the force of such challenges. That we feel this force is a brute social fact, on Brandom’s account. That we engage in a practice in which challenges of entitlement are responded to by giving reasons for entitlement – this is a brute fact. Brandom says nothing about what counts as a good reason – this is to be hashed out entirely in the social practice of asking for and giving reasons itself. But the basic challenge-response structure of entitlement to assertions is a brute (biologically evolved) fact about the nature of the human organism – and this fact, more than any other, is generative of our capacity to wield conceptual content.
Note that ‘entitlement’ is a deontic status, and is thus to be explained in terms of deontic attitudes – attributions of entitlement. So we’re not positing a mysterious thing called ‘entitlement’ here. We’re saying that as evolved organisms we attribute social statuses to each other, challenge those attributions, and that, when challenged, we characteristically offer reasons (are capable of doing so – this capacity is determining of sapience; the claim is not that we always do offer reasons; still less that those reasons are always good reasons). Entitlement can be explained in terms of behaviour. But the behaviour itself is distinctive – the ‘attribute; challenge; response’ structure of that behaviour is distinctive.
This is very confused as formulated here. But I want to start to work through this aspect of Brandom’s apparatus. I’ll aim to continue with that in my next set of posts.
February 8, 2012
So – as I say, in this series of posts I am going to push Brandom’s pragmatics into the background for once, and focus on his inferentialist semantics. There may initially be some replication of earlier blog content here, but we’ll be moving into new terrain soon enough.
What is inferentialism?
Brandom contrasts inferentialism, as a philosophical explanatory strategy, with representationalism, which Brandom regards as the dominant modern philosophical tradition. Representationalism takes the concept of representation as explanatorily fundamental, in our accounts of meaning. Inferentialism, by contrast, takes the concept of inference as explanatorily fundamental. What we’re trying to explain here is sapience, or rationality, or ‘concept-mongering’ (all of which come to the same thing, on Brandom’s account – though of course from the point of view of other theoretical perspectives these concepts might not be equivalent).
Of course there’s no intrinsic need to take either representation or inference as derivative of the other – both concepts could be explanatorily fundamental. But Brandom thinks he can show that reference is derivative of inference – thereby going against much of the modern analytic tradition.
So Brandom starts with inference. That’s our first point.
Second point is the idea of material inference. Brandom contrasts the idea of material inference to that of formal inference – and again the question is one of explanatory priority. A formal inference is one that obeys an explicitly formulated rule of inference, which rule is applicable independent of the content of the inference. A material inference, by contrast, is an inference the goodness of which depends on the content of the claims being inferred from and to.
The modern philosophical tradition, as Brandom characterises it, tends to explain apparently material inferences in terms of formal inferences, by suggesting that apparently material inferences rely on suppressed premises that, if made explicit, render the relevant inference context-independent. So, to use one of Brandom’s favourite examples, if I make the inference “It is raining, so it is wet outside”, a formalist would regard me as possessing a hidden premise here – “If it is raining, then it is wet outside” – and the inferential chain here runs “If it is raining, then it is wet outside; it is raining; therefore it is wet outside”. The actual inference them becomes a purely formal logical one – If X then Y; X; therefore Y – and the actual content of the inference is simply plugged in to this formal operation. The inference itself is independent of that content.
Material inference, by contrast, is inference where the content itself matters for the inference itself – where the inferential move should be understood not in terms of a hidden premise that renders the inference a formal logical one, but in terms of one proposition simply implying another, by virtue of the content of the propositions themselves, without any additional mediating operation.
Brandom believes that material inference is explanatorily prior to formal inference – that formal inference should be explained in terms of material inference, not the other way around.
Brandom has arguments for this – notably Wittgenstein’s regress of interpretations, which Brandom takes to show the unacceptability of formalism (or, in his vocabulary, ‘regulism’); a similar argument is made in Lewis Carrol’s ‘What Achilles Said to the Tortoise’, which Brandom also cites. But Brandom’s arguments aren’t specifically my concern here – for now I’m just interested in articulating his position.
More in my next post.