Hume’s required medium

Instead of continuing my commentary of Hume’s Treatise of Human Nature,[1] I have decided to turn instead to his Enquiry concerning Human Understanding, beginning at section 4.

Due to the foreignness of Hume’s terminology to my own, I believe that if I were to write in-depth comments about his first fifteen paragraphs, I should then spend much time parsing his words, only to then find that his meaning, if interpreted with due charity, is something quite plain and undeniable, and at any rate irrelevant to my project. So I skip to the question at the end of ¶16, which I find curious enough to answer, although, at any rate, the answer was implicit in what I said before.[2]

In the context of our inferring, from some new object’s looking like bread, that it will nourish us, Hume asks:

These two propositions are far from being the same, I have found that such an object has always been attended with such an effect, and I foresee, that other objects, which are, in appearance, similar, will be attended with similar effects. I shall allow, if you please, that the one proposition may justly be inferred from the other: I know in fact, that it always is inferred. But if you insist, that the inference is made by a chain of reasoning, I desire you to produce that reasoning. The connexion between these propositions is not intuitive. There is required a medium, which may enable the mind to draw such an inference, if indeed it be drawn by reasoning and argument. What that medium is, I must confess, passes my comprehension; and it is incumbent on those to produce it, who assert, that it really exists, and is the origin of all our conclusions concerning matter of fact.

OK. Since he asked, I will produce the reasoning. But first, since I quoted from Hume – even for such a short passage – I must make some clarifications to dispel difficulties with his wording:

• First, of course, what I will produce is not the way in which everyone always derives one proposition from the other, but the way in which it may be done validly, which might happen much less often than invalidly.

• Second, I have no pretension that the reasoning between these two propositions “is the origin of all our conclusions concerning matter of fact” – I have no idea why Hume thought that it should be.

• Third, I think that, obviously, no “object” of experience is “attended with” any “effect” always and everywhere, but rather, that it is attended with that effect in a range of contexts. Hume himself must have known this, since he made such a big deal (in ¶2) about it not being logically necessary “that the sun will rise tomorrow” – even the least sceptical philosopher must admit that it will only rise if there are no impediments in place, and we all only differ about how certain we are that there will be no such impediments tomorrow. I want to make this more explicit, so I will add amendments about the context of the observation to both propositions.

Alright, so, the reasoning goes more or less like this:

• Proposition 1. (First Premise) I have found that such an object in such a context has always been attended with such an effect.

• Clarification 1: By “such an object”, I mean a collection of appearances which are precisely such as allow me to understand a certain form.

• Clarification 2: By “such a context”, I mean a different collection of appearances, by which I understand different forms.

• Proposition 2. (Second Premise – Medium) The forms which I understand through these appearances, when I perceive such an object in such a context, are all such as to which I can ascribe the motions which produce the effect.

• Clarification 3: By “forms”, I mean the objects of understanding, as defined in my metaphysics. The relevant fact about them here is, that the same conjunctions of forms are always connected with the same motions, which fact is called final causality.

• Proposition 3. (Conclusion) I foresee, that other objects, which are, in appearance, similar, will be attended with similar effects in similar contexts.

• Clarification 4: By “similar objects”, I mean objects through whose appearances I can understand the same form that I can understand through this object’s appearances, insofar as I can ascribe their motions to it.

• Clarification 5: By “similar contexts”, I mean contexts through whose appearances I can understand the same forms that I can understand through this context’s appearances, insofar as I can ascribe their motions to them.

This could probably be restated more directly, but this will have to do. The way I have chosen to lay it out has the advantage of giving Hume’s (modified) propositions at the beginning and end, with the medium being in the middle, as the name would suggest that it should be.

While ¶17 implies that Hume is passing from this question into a more “positive” argument, he is really just repeating the question in different ways. “May I not clearly and distinctly conceive, that a body, falling from the clouds, and which, in all other respects, resembles snow, has yet the taste of salt or feeling of fire?” You can certainly imagine it; you may be able to conceive of it; you probably have no reason to expect it. If, through the appearance of those other respects, you would be able to perfectly understand the form of snow, then it follows that the taste and feeling do not belong to the nature of snow as you understand it, and that in such a situation, you would have simply found a unique type of snow – one that must have been, intelligibly, brought about by its particular context.

Hume is right in saying, in ¶19, that all, or almost all, propositions about experience are only probable judgments; but this is not because it is impossible to deduce effects from causes. It is rather because we usually do not take care to ascertain the true nature of what appears to us. We do not try to get apodictic knowledge that a car is a car before we get in it; it is sufficient to us that it probably is a car, and that we have no reason to expect otherwise. But we are certain that, if it is a car, then it has an engine, and the power of spinning its wheels in certain conditions, and whatever else we ascribe to the nature of a car.

When Hume says, later on in ¶19, that “all our experimental conclusions proceed upon the supposition, that the future will be conformable to the past”, I take him to be speaking rather obliquely about the fact of final causality, which I mentioned above in Clarification 3. The proof of this fact, as it was given in my metaphysics, is that it is a necessary condition of the fact that any apparent objects are understood at all. It may be consistently denied only by denying that apparent objects are understood, and therefore remaining at the Parmenidean theses about being and non-being; but such a conclusion would break the First Rule of Philosophy. So, a philosopher is compelled, qua philosopher, to accept the alternative.

In ¶20, Hume says:

Nothing so like as eggs; yet no one, on account of this appearing similarity, expects the same taste and relish in all of them. It is only after a long course of uniform experiments in any kind, that we attain a firm reliance and security with regard to a particular event. Now where is that process of reasoning, which, from one instance, draws a conclusion, so different from that which it infers from a hundred instances, that are nowise different from that single one?

I suppose that we might not form this expectation from the first appearances of eggs because, at that point, we do not yet know the nature of eggs. But after we know it, then whenever we see what we understand to be an egg, in what we understand to be an appropriate context, then we know exactly what range of tastes to expect from it. Usually, that is rather too much investigation about a small meal, and we are satisfied with probability about all these understandings; and it really may take many experiments to find which inessential appearances are best relied upon for a probable judgment. (For instance, these.)

I see nothing of interest in the paragraphs 21 through 23, so I pass over them.

Notes

[1] Following a preambular post to my commentaries in general, I have written commentaries of sections 1.1.5 and 1.1.6 of Hume’s Treatise.

As explained in the preambular post, the purpose of my commentaries is to find a plan of topics around which to write my opinions about metaphysics. Not finding them useful for this purpose, I skipped the first four sections of the Treatise, as well as the first three sections of the Enquiry.

[2] While I tend to avoid repetition of my own doctrines – which avoidance is the very reason for this blog – I could not help being engaged by Hume’s question. Generally, I find it difficult to look at rhetorical questions without trying to think of answers for them. So I wrote this post partly as an exercise, and I find this reformulation of my opinions to be interesting enough to be posted. If I ever bring my opinions into more systematic form, though, I should find some way to avoid such repetitions.