This option is known as foundationalism, and it responds to Agrippa’s trilemma by accepting, in line with Option 1, that sometimes a belief can be justified without being supported by any further beliefs. On the face of it, this view might seem prob- lematic for the reason mentioned above regarding how beliefs that are not properly grounded – such as the child’s belief that the moon is a balloon – do not appear to be likely candidates to be counted as justified. What the dominant form of founda- tionalism argues, however, is that some beliefs do not require further justification because they are, in a sense, self-justifying. This type of foundationalism is known as classical foundationalism and it argues that knowledge is structured in such a way that chains of justification end with special self-justifying foundational beliefs which do not stand in need of any further support.
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René Descartes (1596–1650)
I think, therefore I am. (Cogito ergo sum.)
Descartes, Discourse on Method The French philosopher and mathematician René Descartes is one of the founding fathers of modern philosophy. His most famous work is his Meditations on First Philosophy in which, among other things, he offers a radi- cally new way of approaching epistemology.
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Perhaps the most famous exponent of classical foundationalism is Descartes, whom we first saw in Chapter 3. Descartes argued that the foundations for our knowledge were those beliefs that were immune to doubt and which were therefore certain and self-evidently true. The example he gave of such a belief was one’s belief in one’s own existence. As Descartes argued, such a belief is indubitable because in doubting it one proves that one is alive to doubt it, and therefore proves that it is true. Such a belief is therefore by its nature self-justifying, and so does not stand in need of further grounds in order to be justifiably held. In a sense, one’s belief in this proposition is, plausibly, infallible, in that one could not possibly be in error in this regard. If this is right, then any chain of justification which ended with this belief could thus properly stop at this juncture.
The main problem facing classical foundationalism has always been to identify those self-justifying beliefs that can serve as foundations; or at least offer an account of the foundational beliefs that is not unduly restrictive. The difficulty is that it seems there must be some fairly strict constraint put on foundational beliefs if we are to allow them to serve as the basis for our non-foundational beliefs. But if the constraints on foundational beliefs are too strict, then we risk having a set of foundational beliefs which is problematically small.
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Descartes’ idea is that in order to put our knowledge on a secure foundation, it is necessary to first subject it to what he called the ‘method of doubt’. This involves doubting as much as can be doubted among one’s beliefs until one finds the indubitable, and thus epistemologically secure, foundation on which one’s knowledge can be built. In the service of this end, Descartes put forward a number of radical sceptical hypotheses – scenarios which are indistinguisha- ble from normal experience, but in which one is radically in error, such as that one’s experiences are a product of a dream – in order to discover which of his beliefs were immune to doubt. By applying the method of doubt, Descartes was led to the conclusion that the indubitable foundation of our knowledge is our belief in our own existence, since in doubting our existence, we thereby prove that we exist (since how else could we be able to doubt?). Hence the famous claim, ‘I think, therefore I am’.
Ironically, the powerful sceptical arguments that Descartes invented have held more sway than his subsequent anti-sceptical arguments. Accordingly, although it was not his aim to make us sceptical about the possibility of knowledge, this is in fact what his epistemological investigations seem to have achieved.
Aside from his work in epistemology, Descartes made important contributions to just about every other area of philosophy as well. In addition, he also con- ducted research on scientific and mathematical questions, making a longstand- ing contribution to, for example, geometry.
the structure of knowledge 37 For example, suppose one argues, plausibly, that the foundational beliefs had better be those beliefs that one is infallible about – that is, beliefs which just could not be wrong – since only an immunity to error of this sort would ensure that these beliefs could be justified without reliance on any further beliefs. The idea would thus be that the epistemic status of one’s everyday fallible beliefs which could be in error is traced back to infallible foundational beliefs where the regress of justification comes to an end.
The problem, however, is that there are very few (if any) beliefs that we are infalli- ble about, and the candidate beliefs in this regard do not seem to be able to perform the function of supporting most of our everyday beliefs. Take my belief that two plus two makes four, for example, something which I might plausibly take myself to be infallible about, since it is far from obvious how I could be wrong about this (though with a little ingenuity we can think of cases in which even this belief might be rationally in doubt). Even if this is right, it is far from clear how this belief is sup- posed to support the numerous beliefs about the world that I currently hold – such as that I am currently sitting at my desk – since this mathematical belief bears no obvious relation to my beliefs about the world.
The same goes for the belief in one’s existence that we looked at above in our discus- sion of Descartes’ classical foundationalism. How could the great mass of beliefs that I have about the world be dependent upon a very narrow and specific belief of this sort? The only way to deal with this problem is, it seems, to weaken the requirements one sets on foundational beliefs, perhaps allowing that they could be fallible beliefs after all. For example, maybe one’s beliefs about one’s immediate experience – about how the world seems to you, for instance – should be regarded as foundational beliefs.
The problem with this approach, however, is that it faces the problem of explaining why such beliefs deserve to be treated as foundational in the first place (such beliefs are not obviously infallible). That is, we are stuck between two unpalatable options here. Either we set the requirements on foundational beliefs quite high so that they are plausible, but then face the problem of explaining how such a narrow set of foun- dational beliefs can serve as a foundation for all the non-foundational beliefs; or else we set the requirements on foundational beliefs quite low, but then face the problem of explaining just why such beliefs should be treated as foundational at all.
It is thus not clear that we get any more comfort from the threat posed by Agrippa’s trilemma by appealing to a form of foundationalism than we do by appealing to one of the other standard responses to this problem, such as coherentism or infinitism.
CHAPTER SUMMARY
• We began by noting that, intuitively, if we are to have knowledge, then we must be justified in what we believe. We therefore asked the question of what justification is.
• According to Agrippa’s trilemma, there are only three alternatives in this regard, and none of them are particularly appealing on the face of it. The first alternative is to regard one’s belief as being justified by nothing at all; no further grounds. The
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problem with this option is obvious, since if there is nothing supporting the belief, then in what sense can it be justified? (We used the analogy with a house to illus- trate this. A house with no foundations will not stand.) The second alternative is to regard one’s belief as justified by a further ground which, presumably, will be itself another belief. The problem with this suggestion is that this further belief will also need to be justified, since if the original belief is based on an unjustified second belief, then it is hard to see how the second belief can offer any support to the first belief. But if the second belief needs to be justified, then that belief will itself need to be supported by a further belief, and so on indefinitely. We thus have an infinite regress looming. (Consider the analogy with the house again.
A house with an unending series of foundations will not stand.) Finally, there is the third option of allowing the supporting beliefs, at some point in the chain of justification, to be beliefs that have appeared elsewhere in the chain. This option thus allows circular justifications. This third option is not appealing either, how- ever, since a circular chain of justification seems little better than no justification at all. (To return to the analogy, a house with a circular set of foundations, with no foundations holding all the other foundations up, will not stand.) It thus seems hard to fathom how any belief could be justified.
• We considered three responses to Agrippa’s trilemma, where each of them took one of the unpalatable options just mentioned. The first option was infinitism, which holds that an infinite chain of grounds can justify a belief.
• The second response was coherentism, as defended by Quine, which holds that a circular chain of grounds, so long as it has the right sort of properties at any rate (e.g. being large enough), can justify a belief.
• Finally, we looked at foundationalism, and classical foundationalism in particular – as defended by Descartes – which holds that there are some grounds which do not require any further support, and which can thus act as foundations for the beliefs that rest upon them. We noted that what is specific to classical founda- tionalism is that it regards these ‘foundational’ beliefs as having properties which ensure that they are self-justifying – such as the property of being indubitable or infallibly held. The problem facing this view, however, is that it is difficult to find an account of these foundational beliefs that is plausible while at the same time counting a sufficient number of our beliefs as foundational so that they can support the other beliefs we hold.
STUDY QUESTIONS
1 Describe, in your own words, Agrippa’s trilemma. Consider a belief that you hold and then try to use Agrippa’s trilemma to call into question this belief (you may find it helpful to try this with a friend).
2 What is infinitism, and how does it respond to Agrippa’s trilemma? What, if any- thing, is wrong with it?
3 What is coherentism, and how does it respond to Agrippa’s trilemma? What do you think of the claim made by some defenders of coherentism that it offers the best description of how we in fact go about justifying our beliefs? Do you agree?
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the structure of knowledge 39 Assuming that it is true, do you think this fact is relevant to whether or not coherentism is true?
4 What is foundationalism, and how does it respond to Agrippa’s trilemma? Explain, in your own words, what properties foundational beliefs must have according to classical foundationalism, and give three examples of your own beliefs which might be said to have these properties.
5 Why did Descartes think that his belief in his own existence was a foundational belief? Could foundational beliefs of this sort provide support for your beliefs about the world? If so, then explain how. If not, then say why.
INTRODUCTORY FURTHER READING
Bett, Richard (2010) ‘Pyrrhonian Skepticism’, Routledge Companion to Epistemology, S. Bernecker & D. H. Pritchard (eds), Ch. 37, pp. 403–13 (London: Routledge).
A helpful overview of Pyrrhonian scepticism, and its import for the contempo- rary epistemological debate.
Chisholm, Roderick (1989) The Theory of Knowledge (Englewood Cliffs, NJ:
Prentice-Hall). A classic textbook in epistemology which also contains an influ- ential defence of a version of classical foundationalism.
Williams, Bernard (1978) Descartes: The Project of Pure Inquiry (Harmondsworth:
Penguin). A classic introduction to the philosophy of Descartes, paying particular attention to his epistemology.
Williams, Michael (2001) Problems of Knowledge (Oxford: Oxford University Press).
See Chapter 5 for an excellent introduction to Agrippa’s trilemma, and some of the issues that it raises.
ADVANCED FURTHER READING
Bailey, Alan (2002) Sextus Empiricus and Pyrrhonian Scepticism (Oxford: Oxford University Press). A lively treatment of Pyrrhonian scepticism.
Bonjour, Laurence (1985) The Structure of Empirical Knowledge (Cambridge, MA:
Harvard University Press). Perhaps the most comprehensive defence of coher- entism in recent times. Note, however, that Bonjour has since recanted and now advances a form of foundationalism.
Hookway, Christopher (1988) Quine: Language, Experience and Reality (Oxford:
Polity Press). A classic book introducing the philosophy of W. V. O. Quine.
Steup, Mathias, Turri, John & Sosa, Ernest (eds) (2013) Contemporary Debates in Epistemology (2nd edn, Oxford: Wiley). This edited collection contains three use- ful debates relevant to this section: (1) a discussion (§9) between Jim Pryor and Richard Fumerton on foundationalism (via the topic of ‘immediate justification’);
(2) a debate (§10) between Catherine Elgin and James van Cleve on coherent- ism; and (3) a discussion (§11) between Peter Klein and Carl Ginet on the merits of infinitism (Klein is the foremost contemporary advocate of infinitism).
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FREE INTERNET RESOURCES
Comesaña, Juan & Klein, Peter (2019) ‘Skepticism’, Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/skepticism/. See §5 for an overview of Pyrrhonian scepticism – and of Agrippa’s trilemma in particular – and some of the main responses.
Newman, Lex (2019) ‘Descartes’ Epistemology’, Stanford Encyclopedia of Philoso- phy, http://plato.stanford.edu/entries/descartes-epistemology/. A helpful intro- duction to the epistemological ramifications of Descartes’ epistemology.
Thorsrud, Harold (2004) ‘Ancient Greek Skepticism’, Internet Encyclopedia of Philosophy, www.iep.utm.edu/s/skepanci.htm. An overview of ancient scepticism, including discussion of the style of scepticism, known as Pyrrhonian scepticism, which was advocated by Agrippa, and discussion of Agrippa’s trilemma. See espe- cially §3.
Vogt, Katya (2018) ‘Ancient Skepticism’, Stanford Encyclopedia of Philosophy, http://
plato.stanford.edu/entries/skepticism-ancient/. An excellent overview of ancient scepticism, including discussion of the style of scepticism, known as Pyrrho- nian scepticism, which was advocated by Agrippa, and discussion of Agrippa’s trilemma.
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DOI: 10.4324/9781003356110-6
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rationality
• Rationality, justification, and knowledge
• Epistemic rationality and the goal of truth
• The goal(s) of epistemic rationality
• The (un)importance of epistemic rationality
• Rationality and responsibility
• Epistemic internalism/externalism