Version: v1, Published online: 1998
Retrieved October 27, 2021, from https://www.rep.routledge.com/articles/thematic/belief/v-1
3. Belief as a map by which we steer
One obvious fact about belief is the way we use sentences to state what we believe. An equally obvious fact is the connection between belief and behaviour via desire discussed above. F.P. Ramsey (1931) famously captured this idea by describing belief as a map by which we steer. The alternative to LOTH is an account of belief that sees belief as map like.
For LOTH, individual beliefs are fundamental; while on the map view systems of belief are fundamental. Inside us is a hugely complex structure that richly represents how things around us are in an essentially holistic way. When you believe the bank is bigger than the post office, there is no individual structure, no sentence of mentalese in your head, that represents your belief that the bank is bigger than the post office. Rather you believe that the bank is bigger than the post office by having a belief system according to which, among a great many other things, the bank is bigger than the post office. The key point can be made in terms of maps. A map of the Earth might represent the fact that the taller mountains are mostly near the deeper oceans, but there is no part of the map that says just that in the way that there may be a sentence that says just that – for instance the very sentence ‘The taller mountains are mostly near the deeper oceans’. Or consider holograms. Holograms are ’laser photographs’. When light from the laser is projected through the negative, the well known, three dimensional, coloured array is produced. The negative can be thought of as representing things as being the way the coloured array depicts them. However, no part of the negative has special responsibility for some part of the array. Each part contains information about the whole array. In consequence, what happens if you damage part of the hologram is a loss of detail, a blurring, of the three dimensional array, not a loss in any particular part of it.
Many of the phenomena explained by LOTH can equally be explained by the map theory. We noted how LOTH can explain the evolution of belief over time in terms of the causal interactions of the internal sentences with each other, and how beliefs cause behaviour in terms of how the stored sentences figure in the causal path to behaviour. But internal maps guide rockets to their targets and evolve over time. The same goes for the maps we use every day – they guide our behaviour and evolve over time. We noted that LOTH can explain the fact that those with the capacity to believe that the bookshop is bigger than the post office are also able to believe that the post office is bigger than the bookshop. But maps (and holograms) that can represent that the bookshop is bigger than the post office can equally represent that the post office is bigger than the bookshop.
It has recently been argued that there is empirical evidence that our brains represent how things are around us in something like the way an internal map or hologram might. This has led to a renewed interest in the map theory of belief (see Connectionism).
The major question for the map theory concerns whether believing is closed under entailment. On the map theory to believe that p is to have a system of belief according to which p; that is, to have a system that could not be true unless p. But if p entails q, then a system that could not be true unless p must also be a system that could not be true unless q. This means that the map view must accept closure under entailment, the principle that if p entails q, anyone who believes p believes q. But is it not possible to believe that a triangle is equiangular without believing that it is equilateral – as many beginning geometry students know only too well? The usual reply by map theorists is to insist that one who believes that a triangle is equiangular does believe that it is equilateral; what they may lack is knowledge about the right words to capture what they believe. But this is a matter of lively debate.
Jackson, Frank and David Braddon-Mitchell. Belief as a map by which we steer. Belief, 1998, doi:10.4324/9780415249126-V006-1. Routledge Encyclopedia of Philosophy, Taylor and Francis, https://www.rep.routledge.com/articles/thematic/belief/v-1/sections/belief-as-a-map-by-which-we-steer.
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