plain and convincing phaenomenon; which is, that, where-ever by any accident the faculties, which give rise to any impressions, are obstructed in their operations, as when one is born blind or deaf; not only the impressions are lost, but also their correspondent ideas; so that there never appear in the mind the least traces of either of them. Nor is this only true, where the organs of sensation are entirely destroyed, but likewise where they have never been put in action to produce a particular impression. We cannot form to ourselves a just idea of the taste of a pine apple, without having actually tasted it.
This sounds natural enough: the congenitally blind cannot understand colour language, the congenitally deaf can have no idea of the sound of a trumpet or clarinet, and someone who has never tasted pineapple can’t form an idea of what it tastes like. Hume is here arguing for his central doctrine that all our ideas (anything we can talk or think about) have to originate in sense-impressions: we learn what red is by having a visual impression of red, what the taste of pineapple is by having the sensation of tasting pineapple, etc. (Hume would probably have conceded that this need not be literally true: someone might be able to produce a pineapple-tasting compound in the lab and teach us the taste of pineapple by means of it.)
Is Hume right here? What type of claim is he making?
There appear to be two sides to the claim, one apparently psychological, the other concerning understanding. Hume seems to be saying that under certain conditions (in the absence of having tasted pineapple) certain mental contents (or qualia as philosophers would nowadays call them) will not occur. In consequence of this, the person “cannot form a just idea” of the taste. How are these sides connected?
“Isn’t that obvious?” someone may retort: “having an idea of a taste simply consists in feeling or recalling the taste, that is, in undergoing this particular sensation”. But how do we know that someone who has never tasted pineapple (or even a lab-made imitation) will never in fact experience this particular sensation? How are we to exclude the possibility, say, that certain neurological conditions will cause a person to have precisely this sensation when eating cucumber or shrimp, or whatever? Similarly, can we be sure that a congenitally blind person will not in fact have an impression of red and blue dots swimming before him?
The point is that this would make no difference. What matters is that these individuals would have no way of connecting their sensations with the taste of pineapple or with the colours red and blue. (I’m not committing myself on what it would mean actually to attribute experiences of this kind to someone.) The importance of the event of tasting pineapple or seeing an actual coloured object does not lie in its causal efficacy in bringing about a particular sensation; it lies in its constituting a point of reference which guides the speaker in her use of the words - provided of course she knows (e.g. has been told) what she has been tasting or seeing.
What matters are not her mental contents, but the fact that from now on we expect her to be able to carry on certain tasks or to make certain kinds of judgment. Differently put: someone who has seen a red object or has tasted pineapple has access to a sample to which she may appeal in her use of words. She has a mastery of the language-game that someone who has not had these experiences or is incapable of having them does not have. I can tell the first person certain things that I cannot tell the second. (Of course, it isn’t that I can tell the first but not the second what pineapple tastes like - but the first will understand me if I say that something else tastes like pineapple, while the second will not.)
On samples as tools of the language, see Wittgenstein, Philosophical Investigations, §§ 16, 50, 56.
Could this line of thought be applied to the case of horrendous experiences? Are we to think, say, of the loss of a loved one as a “sample” that can be used as a point of reference in describing or comparing experiences? Maybe in some cases, but for the most part, the contexts in which we speak about experiences like grief are radically different from the contexts in which we discuss colours or tastes. I hope to return to this question.
(These reflections were inspired by discussions with Olli Lagerspetz.)