Notes on Hume's Treatise
by G. J. Mattey
PART III. OF KNOWLEDGE AND PROBABILITY
§ IX. Of the effects of other relations and other habits.
We must be scrupulous in accepting the new principles.
The argument might be turned against Hume. Why does experience show that the inference is only according to cause and effect, rather than contiguity and resemblance? Could they not produce belief, as they operate according to the same principles?
We first build up a system of ideas based on memory, "comprehending whetever we remember to have been present, either to our internal perception or senses," and our present perceptions. We call that a reality but do not stop there. We build up a second system of reality, one of judgment, on the basis of cause and effect, where the ideas and their relations do not admit of change.
This is what allows us to expand our horizons beyond what is presented in sense experience. The connections are necessary. The example of Rome is given. Everything believed about it "are nothing but ideas; tho' by their force and settled order, arising from custom and the elation of cause and effect, they distinguish themselves from other ideas, which are merely the offspring of the imagination."
Resemblance and contiguity may co-operate with cause and effect, but they cannot stand on their own, due to the looseness of their process. "There is no manner of necessity for the mind to feign any resembling and contiguous objects; and if it feigns such, there is as little necessity for it always to confine itself to the same, without any difference or variation." Indeed, with experience we learn to guard against "reposing any assurance in tohse momentary glimpses of light, which arises in the imagination from a feign'd resemblance and contiguity."
Cause and effect has the opposite advantages to such feigning. "The objects it presents are fixt and unalterable. The impressions of the memory never change in any considerable degree; and each impression draws along with it a precise idea, which takes its place in the imagination, as something solid and real, certain and invariable."
This can be turned into a proof of Hume's claim that belief is nothing but a lively idea related to a present impression. The enlivening one finds with cause and effect works, though to a diminished degree, with resemblance and contiguity.
Examples are given: with contiguity, the journeys of pilgrims to the places of miracles increase the vivacity of them, having the same effect as a new argument.
With resemblance, we infer from the motion of one body to that of another with which it comes into contact, not because the opposite is a contradiction (there are many natural alternatives) but because the action of the second body resembles that of the first. "Resemblance, then, has the same or a parallel influence with experience; and as the only immediate effect of experience is to associate our ideas together, it follows, that all belief arises from the association of ideas, according to my hypothesis."
Coleman: "Hume speaks as if conceivability and inconceivability admit of degrees, which surely could not be said of logical impossibility." Hume: "the reason, why we imagine the communication of motion to be more consistant and nautral not only than those suppositions, but also than any other natural effect ..." !
We make inferences to the existence of the ocean on the basis of hearing the roaring waters, but those we make based on sight are more lively. This is explained by the resemblance "betwixt the image and the object we infer; which strengthens the relation, and conveys the vivacity of the impression to the related idea with an easier and more natural movement."
Resemblance explains our credulity. The testimony of men points out the cause directly, "and is to be consider'd as an image as well as an effect," as opposed to other effects.
Want of resemblance can almost destroy our causal reasoning, e.g. as concerns our future state. People don't really believe in an afterlife, due to its lack of resemblance. "A future state is so far remov'd from our comprehension, and we have so obscure an idea of the manner, in which we shall exist after the dissolution of the body, that all the reasons we can invent, however strong in themselves, and however much assisted by education, are never able with slow imaginations to surmount this difficulty, or bestow a sufficient authority and force on the idea." We are concerned about the effects of our death on this world.
Roman Catholics do not really believe in eternal torment, given the condemnation they give to slaughters on earth.
Custom does not operate only by constant conjunction, but by constant repetition, e.g. as in EDUCATION. "The frequent repetition of any idea infixes it in the imagination; but cou'd never possibly of itself produce belief, if that act of the mind was, by the original constitution of our nature, annex'd only to a reasoning and comparison of ideas." We can scarcely believe of the dead that they are not doing the usual thing. More than half our opinions are due to education, and "over-ballance those, which are owing either to abstract reasoning or experience." Although education is built almost on the same foundation as cause and effect, philosophers do not recognize it, since it is an artificial rather than natural cause.
An ambiguity in 'imagination': 1) vs. memory, the faculty whereby we form our fainter ideas, 2) vs. reasoning, that faculty excluding demonstrative and probable reasonings.