David Hume

“ I cannot forbear having a curiosity to be acquainted with the principles of moral good and evil, the nature and foundation of government, and the cause of those several passions and inclinations which actuate and govern me. I am uneasy to think I approve of one object, and disapprove of another; call one thing beautiful, and another deformed; decide concerning truth and falsehood, reason and folly, without knowing upon what principles I proceed. ”

“ A scrupulous hesitation to receive any new hypothesis is so laudable a disposition in philosophers, and so necessary to the examination of truth, that it deserves to be complied with, and requires that every argument be produced which may tend to their satisfaction, and every objection removed which may stop them in their reasoning.
I have often observed, that, beside cause and effect, the two relations of resemblance and contiguity are to be considered as associating principles of thought, and as capable of conveying the imagination from one idea to another. ”

“ MR WALPOLE TO MR HUME. Arlington Street, July 26th, 1766.
I cannot be precise as to the time of my writing the King of Prussia's letter, but I do assure you, with the utmost truth, that it was several days before you left Paris, and before Rousseau's arrival there, of which I can give you a strong proof; for I not only suppressed the letter while you staid there, out of delicacy to you, but it was the reason why, out of delicacy to myself, I did not go to see him, as you often proposed to me; thinking it wrong to go and make a cordial visit to a man, with a letter in my pocket to laugh at him. ”

“ A future state is so far removed 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. I rather choose to ascribe this incredulity to the faint idea we form of our future condition, derived from its want of resemblance to the present life, than to that derived from its remoteness. ”

“ All the perceptions of the human mind resolve themselves into two distinct kinds, which I shall call impressions and ideas. The difference betwixt these consists in the degrees of force and liveliness, with which they strike upon the mind, and make their way into our thought or consciousness. Those perceptions which enter with most force and violence, we may name impressions; and, under this name, I comprehend all our sensations, passions, and emotions, as they make their first appearance in the soul. By ideas, I mean the faint images of these in thinking and reasoning ”

“ And, indeed, if we consider the common progress of the thought, either in reflection or conversation, we shall find great reason to be satisfied in this particular. Nothing is more admirable than the readiness with which the imagination suggests its ideas, and presents them at the very instant in which they become necessary or useful. The fancy runs from one end of the universe to the other, in collecting those ideas which belong to any subject. ”

“ In common life 'tis established as a maxim, that the straightest way is always the shortest; which would be as absurd as to say, the shortest way is always the shortest, if our idea of a right line was not different from that of the shortest way betwixt two points.
Secondly, I repeat, what I have already established, that we have no precise idea of equality and inequality, shorter and longer, more than of a right line or a curve; and consequently that the one can never afford us a perfect standard for the other. An exact idea can never be built on such as are loose and undeterminate. ”

“ When I am convinced of any principle, 'tis only an idea which strikes more strongly upon me. When I give the preference to one set of arguments above another, I do nothing but decide from my feeling concerning the superiority of their influence. Objects have no discoverable connexion together; nor is it from any other principle but custom operating upon the imagination, that we can draw any inference from the appearance of one to the existence of another. ”

“ Thus, neither by considering the first origin of ideas, nor by means of a definition, are we able to arrive at any satisfactory notion of substance, which seems to me a sufficient reason for abandoning utterly that dispute concerning the materiality and immateriality of the soul, and makes me absolutely condemn even the question itself. We have no perfect idea of any thing but of a perception. A substance is entirely different from a perception. We have therefore no idea of a substance. Inhesion in something is supposed to be requisite to support the existence of our perceptions. ”

“ Thus, when we affirm that God is existent, we simply form the idea of such a Being as he is represented to us: nor is the existence, which we attribute to him, conceived by a particular idea, which we join to the idea of his other qualities, and can again separate and distinguish from them. But I go farther; and, not content with asserting, that the conception of the existence of any object is no addition to the simple conception of it, I likewise maintain, that the belief of the existence joins no new ideas to those, which compose the idea of the object. ”

“ The fundamental principle of the atheism of Spinoza is the doctrine of the simplicity of the universe, and the unity of that substance in which he supposes both thought and matter to inhere. There is only one substance, says he, in the world, and that substance is perfectly simple and indivisible, and exists every where without any local presence. Whatever we discover externally by sensation, whatever we feel internally by reflection, all these are nothing but modifications of that one simple and necessarily existent being, and are not possessed of any separate or distinct existence. ”

“ In general we may pronounce, that a person, who would voluntarily repeat any idea in his mind, though supported by one past experience, would be no more inclined to believe the existence of its object, than if he had contented himself with one survey of it. Beside the effect of design, each act of the mind, being separate and independent, has a separate influence, and joins not its force with that of its fellows. Not being united by any common object producing them, they have no relation to each other; and consequently make no transition or union of forces. ”

“ In the mean time, I cannot forbear observing, that the great difference in their feeling proceeds, in some measure, from reflection and general rules. We observe, that the vigour of conception which fictions receive from poetry and eloquence, is a circumstance merely accidental, of which every idea is equally susceptible; and that such fictions are connected with nothing that is real. This observation makes us only lend ourselves, so to speak, to the fiction, but causes the idea to feel very different from the eternal established persuasions founded on memory and custom. ”

“ Here, then, I find myself absolutely and necessarily determined to live, and talk, and act like other people in the common affairs of life. But notwithstanding that my natural propensity, and the course of my animal spirits and passions reduce me to this indolent belief in the general maxims of the world, I still feel such remains of my former disposition, that I am ready to throw all my books and papers into the fire, and resolve never more to renounce the pleasures of life for the sake of reasoning and philosophy. ”

“ There are no principles either of the understanding or fancy, which lead us directly to embrace this opinion of the double existence of perceptions and objects, nor can we arrive at it but by passing through the common hypothesis of the identity and continuance of our interrupted perceptions. Were we not first persuaded that our perceptions are our only objects, and continue to exist even when they no longer make their appearance to the senses, we should never be led to think that our perceptions and objects are different, and that our objects alone preserve a continued existence. ”

“ The straining of the imagination always hinders the regular flowing of the passions and sentiments. A tragic poet, that would represent his heroes as very ingenious and witty in their misfortunes, would never touch the passions. As the emotions of the soul prevent any subtile reasoning and reflection, so these latter actions of the mind are equally prejudicial to the former. The mind, as well as the body, seems to be endowed with a certain precise degree of force and activity, which it never employs in one action, but at the expense of all the rest. ”

“ To give a child an idea of scarlet or orange, of sweet or bitter, I present the objects, or, in other words, convey to him these impressions; but proceed not so absurdly, as to endeavour to produce the impressions by exciting the ideas. Our ideas, upon their appearance, produce not their correspondent impressions, nor do we perceive any colour, or feel any sensation merely upon thinking of them. On the other hand we find, that any impression, either of the mind or body, is constantly followed by an idea, which resembles it, and is only different in the degrees of force and liveliness. ”

“ A painter, who intended to represent a passion or emotion of any kind, would endeavour to get a sight of a person actuated by a like emotion, in order to enliven his ideas, and give them a force and vivacity superior to what is found in those, which are mere fictions of the imagination. The more recent this memory is, the clearer is the idea; and when, after a long interval, he would return to the contemplation of his object, he always finds its idea to be much decayed, if not, wholly obliterated. ”

“ When every thing is annihilated in the chamber, and the walls continue immovable, the chamber must be conceived much in the same manner as at present, when the air that fills it is not an object of the senses. This annihilation leaves to the eye that fictitious distance, which is discovered by the different parts of the organ that are affected, and by the degrees of light and shade; and to the feeling, that which consists in a sensation of motion in the hand, or other member of the body. In vain should we search any farther. ”

“ They do well to keep themselves in their present situation; and, instead of refining them into philosophers, I wish we could communicate to our founders of systems, a share of this gross earthy mixture, as an ingredient, which they commonly stand much in need of, and which would serve to temper those fiery particles, of which they are composed. While a warm imagination is allowed to enter into philosophy, and hypotheses embraced merely for being specious and agreeable, we can never have any steady principles, nor any sentiments, which will suit with common practice and experience. ”

“ The whole globe of the earth, nay, the whole universe may be considered as an unite. That term of unity is merely a fictitious denomination, which the mind may apply to any quantity of objects it collects together; nor can such an unity any more exist alone than number can, as being in reality a true number. But the unity, which can exist alone, and whose existence is necessary to that of all number, is of another kind, and must be perfectly indivisible, and incapable of being resolved into any lesser unity. ”

“ There is scarce a moment of my life, wherein there is not a similar instance presented to me, and I have not occasion to suppose the continued existence of objects, in order to connect their past and present appearances, and give them such an union with each other, as I have found, by experience, to be suitable to their particular natures and circumstances. Here, then, I am naturally led to regard the world as something real and durable, and as preserving its existence, even when it is no longer present to my perception. ”