David Hume is today the philosopher most often associated with what might be termed ‘radical empiricism’. The problem, of course, as I have pointed out on this blog before, is that he was not the originator of what should properly be recognised as a conceptual revolution. More than this, the thought of the person from whom he took his ideas was completely perverted in the process.
The person whose ideas have been tampered with was, of course, the Irish philosopher George Berkeley. It was George Berkeley who lay the ground for radical empiricism with his observation that all abstract general ideas are merely instances of particular ideas. To get a handle on this we may as well follow Berkeley’s argument closely. In his Principles of Human Knowledge he quotes John Locke on what an abstract general idea is.
Abstract ideas are not so obvious or easy to children or the yet unexercised mind as particular ones. If they seem so to grown men it is only because by constant and familiar use they are made so. For, when we nicely reflect upon them, we shall find that general ideas are fictions and contrivances of the mind, that carry difficulty with them, and do not so easily offer themselves as we are apt to imagine. For example, does it not require some pains and skill to form the general idea of a triangle (which is yet none of the most abstract, comprehensive, and difficult); for it must be neither oblique nor rectangle, neither equilateral, equicrural, nor scalenon, but all and none of these at once? In effect, it is something imperfect that cannot exist, an idea wherein some parts of several different and inconsistent ideas are put together. It is true the mind in this imperfect state has need of such ideas, and makes all the haste to them it can, for the conveniency of communication and enlargement of knowledge, to both which it is naturally very much inclined. But yet one has reason to suspect such ideas are marks of our imperfection. At least this is enough to show that the most abstract and general ideas are not those that the mind is first and most easily acquainted with, nor such as its earliest knowledge is conversant about.
But Berkeley goes on to contest this. Indeed, he claims that such abstract general ideas are really only so much nonsense. He writes,
If any man has the faculty of framing in his mind such an idea of a triangle as is here described, it is in vain to pretend to dispute him out of it, nor would I go about it. All I desire is that the reader would fully and certainly inform himself whether he has such an idea or no. And this, methinks, can be no hard task for anyone to perform. What more easy than for anyone to look a little into his own thoughts, and there try whether he has, or can attain to have, an idea that shall correspond with the description that is here given of the general idea of a triangle, which is “neither oblique nor rectangle, equilateral, equicrural nor scalenon, but all and none of these at once?”
It was this move that allowed Hume to do away with the abstract general idea of causality. For Hume, as is well-known, causes are only known in their particularity. Just because the sun rises today does not mean it will not rise tomorrow. This is known as Hume’s ‘scepticism’ and it leads to the conclusion that we can only know what is (a) immediately given to our sense and (b) what is inscribed in our memory by previous sense impressions. Thus there is no rational reason to argue that the sun will rise tomorrow based on past instances of the sun rising and so forth.
Later on Hume would argue against his own theoretical scepticism in his A Treatise on Human Nature as follows,
Shou’d it here be ask’d me, whether I sincerely assent to this argument, which I seem to take such pains to inculcate, and whether I be really one of those sceptics, who hold that all is uncertain, and that our judgment is not in any thing possest of any measures of truth and falshood; I shou’d reply, that this question is entirely superfluous, and that neither I, nor any other person was ever sincerely and constantly of that opinion. Nature, by an absolute and uncontroulable necessity has determin’d us to judge as well as to breathe and feel; nor can we any more forbear viewing certain objects in a stronger and fuller light, upon account of their customary connexion with a present impression, than we can hinder ourselves from thinking as long as we are awake, or seeing the surrounding bodies, when we turn our eyes towards them in broad sunshine. Whoever has taken the pains to refute the cavils of this total scepticism, has really disputed without an antagonist, and endeavour’d by arguments to establish a faculty, which nature has antecedently implanted in the mind, and render’d unavoidable. (Part IV, Section I)
In actual fact we are back to Berkeley’s position on the matter, it’s just that Hume has not explicitly stated what he was doing. For Berkeley any order in the chaos of particular ideas that we experience as human’s is due to the fact that God puts this order there for us to find. So, Berkeley’s answer to the scepticism that he knew was implicit in his work was that people should have Faith.
Now, look again at that passage from Hume: is he not telling us the same thing? I think it rather obvious that he, in fact, is. He is just replacing the term ‘God’ in Berkeley’s argument with the term ‘Nature’. Rather than saying that God is responsible for the order that we encounter the world Hume claims that Nature has “implanted” a “faculty in the mind” that gives rise to this order. What is this metaphysical entity that Hume calls Nature? One would be forgiven for thinking that it was, in fact, a synonym for ‘God’.
Regardless, however, the implications are perfectly clear: for Hume, just as for Berkeley, the continuity of our perceptions is based on Faith — whether that Faith be in a mysterious entity called ‘God’ or a mysterious entity called ‘Nature’ is really a secondary question.
This was again recognised by the French phenomenologist Maurice Merleau-Ponty. He recognised it in what he referred to as ‘perceptual faith’ by which he meant a Faith in our perceptions that comes, as it were, inbuilt into them and which is not subject to further reflection. In his work The Visible and the Invisible he writes,
It is a question not of putting the perceptual faith in place of reflection, but on the contrary of taking into account the total situation, which involves reference from the one to the other. What is given is not a massive and opaque world, or a universe of adequate thought; it is a reflection which turns back over the density of the world in order to clarify it, but which, coming second, reflects back to it only its own light. (p35)
What Merleau-Ponty realised, as had Berkeley (and which Hume had carelessly neglected), was that Reason as such is based on Faith. There is a point at which our belief in certain rationalistic ideas is actually wholly Faith-based and that, lest we fall into total scepticism (which, as Hume pointed out, we never actually do) we must accept this aspect of Faith that undergirds our Reason. What meaning we give to this is, of course, entirely personal.
All of this has a bearing on, for example, the use of probabilistic reasoning in economics. The use of such techniques are always, when you strip them right back, based on a certain Faith in the validity of the causal chain under scrutiny. This Faith is usually placed both on some probability distribution and in the person of the researcher who trusts himself that he has chosen the ‘correct’ criteria for testing. (And, conversely, does not ‘trust’ other researchers who come up with different results; this is the point at which such Faith-based arguments becomes hermetic, sealed and not open to criticism). There is usually another Leap of Faith in assuming that the future will mirror the past in some sense — i.e. a Faith placed in the fact that the data under scrutiny is ergodic.
Most researchers using such techniques are completely blind to this: they just manipulate the symbols and have no need to question their Faith in them. This, of course, is deeply problematic, but it is built into the structure of the discourse of probability and how it relates to economics through econometrics. What these discourses do is they provide a firm means by which those using them may, in a very real sense, have Faith in their causal inferences. The danger is that such discourses also allow researchers to elide argument from the outside and never question their Faith in their ventures; simply for the fact that, as in dogmatic religion, Faith is given from the outside.
All the criticisms one sees of probabilistic reasoning is a simple questioning of certain of the tenets of Faith. While I have no real problem with such Faith-based arguments per se — indeed, I recognise them as necessary — I do think that often cheap rubbish is sold to unquestioning people. As we know from cults, when dealing with issues of Faith it is possible to convince vulnerable people of any nonsense so long as it provides a firm ground for their life and their activities. Econometric reasoning is mainly nonsense and the reason that it is sold so easily is because economists, whose practice is so uncertain and so open to error, are in an insecure ontological position that has them fall back uncritically on any garbage that provides them with a Faith that comes complete with a false mantle of scientificity.