A Treatise of Human Nature.

BOOK I. OF THE UNDERSTANDING

Rules by which to judge of causes and effects.

"Since therefore 'tis possible for all objects to become causes or effects to each other, it may be proper to fix some general rules, by which we may know when they really are so.

1. The cause and effect must be contiguous in space and time.
2. The cause must be prior to the effect.
3. There must be a constant union betwixt the cause and effect. 'Tis chiefly this quality, that constitutes the relation.
4. The same cause always produces the same effect, and the same effect never arises but from the same cause. . .
5. . . . where several different objects produce the same effect, it must be by means of some quality, which we discover to be common amongst them. . .
6. . . . The difference in the effects of two resembling objects must proceed from that particular, in which they differ. . .
7. When any object encreases or diminishes with the encrease or diminution of its cause, 'tis to be regarded as a compound effect, deriv'd from the union of the several different effects, which arise from the several different parts of the cause. . .
8. . . . an object which exists for any time in its full perfection without any effect, is not the sole cause of that effect, but requires to be assisted by some other principle, which may forward its influence and operation. . .

Here is all the LOGIC I think proper to employ in my reasoning . . ."^1a

"We have no perfect idea of any thing but of a perception."^1b

" . . . [A]n object may exist, and yet be no where: and I assert, that this is not only possible, but that the greatest part of beings do and must exist after this manner."^1c

An Enquiry Concerning Human Understanding.

" . . . [W]e may divide all the perceptions of the mind into two classes of species . . . The less forcible and lively are commonly denominated Thoughts or Ideas. The other species . . . Let us . . . call them Impressions . . . By the term impression . . . I mean all our more lively perceptions, when we hear, or see, or feel, or love, or hate, or desire, or will.^"2a

" . . . [N]ature has established connexions among particular ideas, and that no sooner one idea occurs to our thoughts than it introduces its correlative, and carries our attention towards it . . . These principles of connexion or association we have reduced to three, namely, Resemblance, Contiguity and Causation; which are the only bonds that unite our thoughts together, and beget that regular train of reflection or discourse, which, in a greater or less degree, takes place among all mankind.^"2b LOCKE

"This transition of thought from the cause to the effect proceeds not from reason. It derives its origin altogether from custom and experience.^"2c LOCKE

"To begin with clear and self-evident principles, to advance by timorous and sure steps, to review frequently our conclusions, and examine accurately all their consequences; though by these means we shall make both a slow and a short progress in our systems; are the only methods, by which we can ever hope to reach truth, and attain a proper stability and certainty in our determinations.^"2d LOCKE

" . . . [T]here is no such thing as abstract or general ideas . . .^"2e

"Whatever is may not be. No negation of a fact can involve a contradiction. The non-existence of any being, without exception, is as clear and distinct an idea as its existence.^"2f LOCKE

Selected Essays.

"Mankind are, in all ages, caught by the same baits: the same tricks played over and over again, still trepan them."³ HEGEL MACHIAVELLI

¹ David Hume (1711-1776). A Treatise of Human Nature. Mineola, NY: Dover Publications, Inc., 2003. [Slightly altered republication of the work published by Oxford at the Clarendon Press, London, 1888, itself a reprint of the original edition in three volumes published in London, 1739-1740.]
BOOK I. Of the Understanding.
PART III. Of knowledge and probability.
^a XV. Rules by which to judge of causes and effects, at 124-125.
Part IV. Of the sceptical and other systems of philosophy
^b V. Of the immateriality of the soul, at 167.
^c Ibid., 168.

² David Hume (!711-1776). An Enquiry Concerning Human Understanding. Mineola, NY: Dover Publications, Inc., 2004. [Unabridged republication of the work originally published in English Philosophers of the Seventeenth and Eighteenth Centuries by O. F. colliers & Son Corporation, New York, 1910.]
^a II. Of the Origin of Ideas, at 9.
^b V. Sceptical Solutions of These Doubts, at 31.
^c Ibid., at 33-34.
^d XII. Of the Academical or Sceptical Philosophy, at 97.
^e Ibid., at 102.
^f Ibid., at 106.

³ David Hume (1711-1776). Selected Essays (1741-1742). Edited with an Introduction by Stephen Copley and Andrew Edgar, 1993. Oxford, England: Oxford University Press, at 214.