But observations are... fallible, a fact we obscure when we
use words like ‘observe’ so that by mere definition we can’t observe what isn’t
there. So I will not use ‘observe’, ‘see’, ‘hear’, etc. in that misleading way.
When my looking to see if there are sparrows makes me believe that there are, I
shall say that I see that there are, whether there are or not. For there might
not be: our senses always can give us false beliefs and sometimes do.
Observation no more entails the truth of the beliefs it gives us than induction
does. How then can it warrant them? [Mellor 1988]
The question here is how observation warrants the truth of
the beliefs it motivates. Mellor’s answer is that causal links enable
observations to warrant beliefs because, he claims, the fact that makes a
belief true is what causes the belief to be held. (Given that this is supposed
to be the warrant observation provides, the causal connection must (I assume)
be via a suitable sensory path.)
The claim that observation isn’t
factive can now be accommodated via the further – independently plausible –
claim that causation isn’t deterministic. If causation merely raises the
chances of its effects (ie if it doesn’t have to make the chances of its
effects = 1) then thinking that one sees a sparrow can warrant a belief in
sparrows by suitably raising the chances of their being sparrows, though not to
1 and other things can also cause a belief in sparrows.
This then serves as a point of
departure for thinking about the warrant of the truth of beliefs produced by
induction. In this case, it cannot be that the facts that cause the beliefs are
the same facts that make those beliefs true because induction isn’t a kind of
direct perception of the future, for example. Rather, the facts that cause the
inductive belief are the inductive base: the premises not the conclusion of the
inductive inference. So what warrants the truth of the resultant belief in the
conclusion?
Mellor’s answer is that the warrant is
the lawlike connection between the truth of the premises and the truth of the
conclusion. Providing that the world is suitably lawlike, induction is
warranted. Hence a quotation at the start of the lecture from Frank Ramsey ‘we are all convinced by inductive arguments, and our
conviction is reasonable because the world is so constituted that inductive
arguments lead on the whole to true opinions’. But the laws need not be
deterministic to provide a warrant. They just need to raise the chances of
effects sufficiently.
Suppose, to simplify the discussion (it’s not essential),
that your inferential habits are deterministic, like your mass: this habit
would always make you infer that a lecture was terse, never that it wasn’t. And
suppose that every lecture has some chance of being terse. Then whenever your
premise (‘this is a lecture’) is true, your conclusion (‘this is terse’) has
some chance of being true. And if this chance is high enough, your prediction
is warranted. [Mellor 1988]
Being warranted depends on what the
laws of nature are. But providing there is a sufficient natural uniformity,
induction is warranted. Now putting it like this (Mellow does not) invites a
comparison with versions of the problem of induction going back to Hume in
which defences of induction that invoke the uniformity of nature face a
problem. Since a claim about uniformity is not a ‘relation of ideas’ it must be
a matter of fact. But it isn’t a directly perceivable matter of fact and thus
must be the result of an inference from what can be observed. What inference?
Well induction. So if the defence of induction requires appeal to the
uniformity of nature, it looks to be circular. Here’s Mellor’s summary of that
worry.
So far so good - provided these warrants needn’t be
self-intimating. I say the law that all tree frogs are green warrants my
inferring that something is green from the fact that it’s a tree frog. But
suppose I must know that I have this warrant. Then I must know this law. So I
must believe it, and this belief must be warranted. But the law entails the
very inference which it’s meant to warrant: tree frogs can’t all be green
unless this one is. So unless my inference is warranted already, my belief in
the law won’t be warranted. Thus to claim that the law is what warrants this
particular application of it simply begs the question of whether it’s warranted
at all. [Mellor 1988]
The solution is to part company with an
assumption built into Hume’s version: that justification is self-intimating or that
to be justified, one must know the justification. Mellor’s solution is an externalist
denial of that. One can be warranted without knowing the warrant.
This is the stock objection to contingent solutions to the
problem of induction: they beg the question. And so they would if
belief-warrants had to be self-intimating. But … they don’t. The law that all
tree frogs are green can warrant the habit of inference which induction will
then give me, just because I needn’t know that it does. I can know by induction
that a frog is green without knowing that law, just as I can know that it’s
green by looking at it without knowing I’m not colour-blind. I may know the
law, just as I may know that I’m not colour-blind; but I needn’t. So my saying
that the law is what warrants this induction doesn’t beg the question. [Mellor 1988]
The lecture conducts some further
business. Because of the nature of the appeal to indeterministic or
probabilistic laws in this epistemological context, Mellor reminds us that
these can be thought of as objective chances with mind-independent causes and
effects. He also explains the advantage of larger sample sizes in the premises
of inductions and why counter-induction is generally a less good strategy than
induction in a lawlike world but that no strategy triumphs in a lawless world. But
the general idea is that a possibly probabilistic but generally lawlike
universe warrants a form of inference which moves between nomologically related
properties.
One question this prompts is the
relation of warrant and truth. In the case of observation, there is a potential
for a gap which isn’t there in a disjunctive account. Since ‘seeing’ a sparrow
does not entail that there is a sparrow, a warranting but merely probabilistic
relation between sparrows and beliefs in sparrows can coincide with the falsity
of a belief. So Mellor accepts the idea that two subjects can be equally warranted
in their beliefs, one can be false and the other true but the latter subject
nevertheless have knowledge. That seems odd as it seems that the fact that
their belief is true is, relative to their counterpart, a matter of some luck
(likely though they are to be right).
A disjunctivist like McDowell can
attempt to account for the fallibility of observation by conceding that whilst
that faculty as a whole is fallible, its exercise on particular occasions falls
into two sub-groups: actually seeing the sparrow or merely thinking one sees
the sparrow. In the good disjunct, no probability is in play: the sparrow is
simply there in view. So the warrant in the good disjunct is of a quite
different kind to that in the bad disjunct. (The worry now is whatever is surprising
about the idea that warrant and truth cannot come apart symmetrically.)
Returning to Mellor, in one kind of
case of failed induction, there seems to be a similar possibility for a false
but warranted induction: the unlucky case in which a probabilistic connection
fails to yield the fact that fits the inductively supported conclusion. But I
wonder about a case in which, for fully deterministic reasons, one causal
regularity is trumped by another. The regular spinning of the Earth may be
interrupted by a supernova, eg. In that case, the sun’s previous behaviour
considered alone might be thought to warrant the inductive belief that it would
rise the next day but the physical system as a whole suggests that such a
belief is not, in fact, warranted. The former approach would require some
principles of individuation of the physical system considered independently of
the subject’s grasp which seems tricky. But the latter approach would undermine
the possibility, in deterministic cases, of warranted but false beliefs. Whilst
it might seem the exercise of epistemic responsibility, the inference isn’t in
fact warranted. This seems odd.
The appeal to me, however,
of Mellor’s approach is that it sidesteps the ‘internalist’ version of the problem
of induction. Not requiring that one knows the principle of uniformity of nature
more generally, or the local laws more specifically, blocks the circularity which
Hume stresses. So is there a way of embracing that and which maps something like
a disjunctivist ‘correction’ of the warrant of observation onto induction? Not quite,
I think.
Note that there are opposing
tensions in calling McDowell’s disjunctivist picture of seeing ‘internalist’ and
‘externalist’. It is externalist, or perhaps more precisely not internalist, insofar
as the fact that one occupies the good or the bad disjunct depends on a worldly
favour which is beyond what the subject can control (hence the rejection of the
interiorization of the space of reasons). But it is internalist, or rather not externalist,
insofar as, if one is in the good disjunct, the seen sparrow is simply there for the subject, in no sense external to their experience
(contra the highest common factor approach).
At first sight, it doesn’t
seem possible to play quite this game with the inductive base. One cannot simply
see in the observed past behaviour of ‘sunrise’, for
example, the next day’s rise, that very event. Recall that in setting up Hume's
problem, the connection between past and future regularities is a matter of fact
rather than a relation of ideas. But then, within the class of matters of fact,
such a regularity is not directly observable and must be extracted or inferred from
what is observable (past regularities). At that point, we realise that the principle
needed to do this presupposes the very thing that was supposed to be the conclusion
of the inference.
With Mellor in mind, we
might suggest that the observed past sunrises physically necessitate the next day’s
rise. But if so, it isn’t so clear what the difference is in what is available to
the subject between observing past sunrises which necessitate a future sunrise and
sunrises which do not. The subsequent necessitation seems to be something external
to what is observed and thus external to the subject’s grasp. So the feature of
the disjunctivist account of observation which merits the description 'internal
or at least not external' does not apply to Mellor's view of the law that connects
past to future sunrises. Such a law is not part of what the subject can take in.
In McDowell’s discussion
of the testimonial transmission of knowledge, he suggests that we speak of hearing,
in another’s words, that things are thus and so. There is also here a possible line
of analogy in that, for one to hear that things are thus and so, the interlocutor
must be reliable and that is not something one typically ensures oneself. So their
reliability is not in their utterance but is a precondition for hearing
in their utterance the facts.
There is, however, also
a potential disanalogy to induction here. The ‘content’ that the sun will rise tomorrow
– or the sun’s rise, tomorrow – is not there in the induction base to be embraced. It seems
that it must be inferred from that. This might suggest that there isn’t an equivalent
idea to the mix of internal and external that characterises observation in the good
disjunct. The link from past to future seems, as it is with Mellor’s account, an
external addition to is observed. But the problem of making the connection external
is that were it ‘blankly external’, as McDowell sometimes says, then it is hard
to see how it can contribute the subject’s epistemic standing.
To get something akin to
the disjunctivist account of the good disjunct for observation for the case of induction,
I think we need to think along these lines. The subject who bases a prediction for
the future on experience of past events must not merely take the past facts as atomic.To
have a bearing on the future, they see a kind pattern or ‘habit’ in the sun’s behaviour.
They see in the past behaviour of the sun its ongoing, and hence future implicating,
pattern. And if the pattern really is ongoing – by contrast with a kind of bad disjunct
in which the seeming pattern is not really there – then the subject does have a
justification which balances internal and external.
Hume’s problem of induction
is generated not just from the fact that the inference from past to future is not
a ‘relation of ideas’ and hence must be a matter of fact but also because it is
not a matter for direct perception and hence must be an inference. But perhaps the
latter distinction does not neatly divide two aspects of the inductive base: atomic
facts and subsequent inference. One sees in the facts the ongoing pattern.
McDowell’s own comments
on the problem of induction are aimed rather differently. He attempts to deconstruct
the starting assumption which compares induction with observation unfavourably.
But I wonder whether by denying the separation of observation and induction they
also sustain something like a disjunctivist view of seeing the enduring pattern
in the past events:
there cannot be a predicament
in which one is receiving testimony from one’s senses but has not yet taken any
inductive steps. To stay with the experience of colour... colour experience’s being
testimony of the senses depends on the subject’s already knowing a good deal about,
for instance, the effect of different sorts of illumination on colour appearances...
[McDowell 1998: 411]
So the supposed predicament
of the inductive sceptic is a fiction... Hume’s formulation can seem to describe
a predicament only if one does not think through the idea that its subject already
has the testimony of the senses and this means that scepticism about induction can
seem gripping only in combination with a straightforwardly interiorizing epistemology
for perception. [McDowell 1998: 412].
PS: a few more thoughts on this are here.
McDowell, J. (1995) ‘Knowledge and the Internal’ Philosophy and Phenomenological Research 55: 877-893 reprinted in McDowell, J. (1998) Meaning knowledge and reality, Cambridge, Mass.: Harvard University Press
Mellor, H. (1988) ‘The warrant of induction’ http://www.dspace.cam.ac.uk/handle/1810/3475.
