A footprint in the sand

This is not a footprint in the sand

I was bemused a while ago to receive an email from Big Jim in which he described the great Scottish Philosopher as 'that clown Hume', bemused because he is after all the great Scottish philosopher.

But I have been thinking about his empiricism recently and recalling what I had long ago forgotten, that the distinction between impressions and ideas upon which everything in Hume rests, rests in fact upon a metaphor which, if we take it seriously, undermines everything he says. One always forgets things in philosophy, partly because one is carried along by the flow of philosophical writing in which authors settle too readily on a premise and then race to a conclusion. Everything depends for Hume on tracing 'ideas' back to the 'impressions' of which they are faint copies (in fact these ideas or images are better candidates for 'impressions' than the alleged impressions themselves) and Hume's sceptical rejection of our ideas of necessity, causality, the spatio-temporal continuity of bodies, the permanence of the self or soul, relies on obvious features of what he calls impressions as they impress themselves, as it were, upon our minds. Such impressions last as long as they are perceived, they do not hang around unperceived, so what grounds do we have for talking about the same body when all we are aware of is a qualitatively identical impression, etc.

Which takes us back to the footprint in the sand. Now that is an impression, an impression of a foot, just as a crater is an impression of a meteor or a child's handprint on a piece of paper an impression of their hand, etc. The footprint gives us some idea of the size and shape of a particular foot. It doesn't look like a foot, but it shows us the outline and the indentation tells us something about the weight of the body relative to the softness of the ground. But impressions of this kind belong within our epistemological economy and are not its basis. We can reason from footprint to foot because we know about footprints and about feet, and we know what an impression is and why and how it is made. The idea of an impression is the idea of an impression of something that is known independently. In that case Hume's impressions are not impressions, he has no title to that word. We don't see impressions of bodies, we see bodies, we see things, stones, for instance, on a raised beach. The Humean trick lies in persuading us that what we really see is only ... This is not an argument against scepticism about empirical knowledge, it is just an argument against Hume. It doesn't deliver us back a permanent self, either, for that there is no such thing is not to be argued for in terms of Hume's failure to find a self.

The whole discussion of empirical knowledge is vitiated, it seems to me, by a failure to take seriously the grammatical or conceptual difference between talk of objects which are essentially mind-dependent, and things, which are not. Philosophers are always talking about objects as though they were talking about things and things as though they were objects, and they get the grammars tangled.

Now how can I say this in a semi-public space without sounding mad: when I say that we see things and not merely impressions of things, I am not asserting in Johnsonian spirit that we see things, I am saying that it is a mistake, conceptually, to claim that we see impressions of things. What we see are things and if we are to raise sceptical questions, as we should, in a spirit of epistemological vigilance, then we must address the issues in those terms, and not in terms of impressions, which is a bad place to start from.