SECTION V.: Of relations. - David Hume, A Treatise of Human Nature 
A Treatise of Human Nature by David Hume, reprinted from the Original Edition in three volumes and edited, with an analytical index, by L.A. Selby-Bigge, M.A. (Oxford: Clarendon Press, 1896).
About Liberty Fund:
Liberty Fund, Inc. is a private, educational foundation established to encourage the study of the ideal of a society of free and responsible individuals.
The text is in the public domain.
Fair use statement:
This material is put online to further the educational goals of Liberty Fund, Inc. Unless otherwise stated in the Copyright Information section above, this material may be used freely for educational and academic purposes. It may not be used in any way for profit.
- Editor’s Preface.
- Book I: Of the Understanding
- Part I.: Of Ideas, Their Origin, Composition, Connexion, Abstraction, &c.
- Section I.: Of the Origin of Our Ideas.
- Section II.: Division of the Subject.
- Section III.: Of the Ideas of the Memory and Imagination.
- Section IV.: Of the Connexion Or Association of Ideas.
- Section V.: Of Relations.
- Section VI.: Of Modes and Substances.
- Section VII.: Of Abstract Ideas.
- Part II.: Of the Ideas of Space and Time.
- Section I.: Of the Infinite Divisibility of Our Ideas of Space and Time.
- Section II.: Of the Infinite Divisibility of Space and Time.
- Section III.: Of the Other Qualities of Our Ideas of Space and Time.
- Section IV.: Objections Answer’d.
- Section V.: The Same Subject Continu’d.
- Section VI.: Of the Idea of Existence, and of External Existence.
- Part III.: Of Knowledge and Probability.
- Section I.: Of Knowledge.
- Section II.: Of Probability; and of the Idea of Cause and Effect.
- Section III.: Why a Cause Is Always Necessary.
- Section IV.: Of the Component Parts of Our Reasonings Concerning Cause and Effect.
- Section. V.: Of the Impressions of the Senses and Memory.
- Section VI.: Of the Inference From the Impression to the Idea.
- Section VII.: Of the Nature of the Idea Or Belief.
- Section VIII.: Of the Causes of Belief.
- Section IX.: Of the Effects of Other Relations and Other Habits.
- Section X.: Of the Influence of Belief.
- Section XI.: Of the Probability of Chances.
- Section XII.: Of the Probability of Causes.
- Section XIII.: Of Unphilosophical Probability.
- Section XIV.: Of the Idea of Necessary Connexion.
- Section XV.: Rules By Which to Judge of Causes and Effects.
- Section XVI.: Of the Reason of Animals.
- Part IV.: Of the Sceptical and Other Systems of Philosophy.
- Section I.: Of Scepticism With Regard to Reason.
- Section II.: Of Scepticism With Regard to the Senses.
- Section III.: Of the Antient Philosophy.
- Section IV.: Of the Modern Philosophy.
- Section V.: Of the Immateriality of the Soul.
- Section VI.: Of Personal Identity.
- Section VII.: Conclusion of This Book.
- Book II: Of the Passions
- Part I.: Of Pride and Humility.
- Section I.: Division of the Subject.
- Section II.: Of Pride and Humility; Their Objects and Causes.
- Section III.: Whence These Objects and Causes Are Deriv’d.
- Section IV.: Of the Relations of Impressions and Ideas.
- Section V.: Of the Influence of These Relations On Pride and Humility.
- Section VI.: Limitations of This System.
- Section VII.: Of Vice and Virtue.
- Section VIII.: Of Beauty and Deformity.
- Section IX.: Of External Advantages and Disadvantages.
- Section X.: Of Property and Riches.
- Section XI.: Of the Love of Fame.
- Section XII.: Of the Pride and Humility of Animals.
- Part II.: Of Love and Hatred.
- Section I.: Of the Objects and Causes of Love and Hatred.
- Section II.: Experiments to Confirm This System.
- Section III.: Difficulties Solv’d.
- Section IV.: Of the Love of Relations.
- Section V.: Of Our Esteem For the Rich and Powerful.
- Section VI.: Of Benevolence and Anger.
- Section VII.: Of Compassion.
- Section VIII.: Of Malice and Envy.
- Section IX.: Of the Mixture of Benevolence and Anger With Compassion and Malice.
- Section X.: Of Respect and Contempt.
- Section XI.: Of the Amorous Passion, Or Love Betwixt the Sexes.
- Section XII.: Of the Love and Hatred of Animals.
- Part III.: Of the Will and Direct Passions.
- Section I.: Of Liberty and Necessity.
- Section II.: The Same Subject Continu’d.
- Section III.: Of the Influencing Motives of the Will.
- Section IV.: Of the Causes of the Violent Passions.
- Section V.: Of the Effects of Custom.
- Section VI.: Of the Influence of the Imagination On the Passions.
- Section VII.: Of Contiguity, and Distance In Space and Time.
- Section VIII.: The Same Subject Continu’d.
- Section IX.: Of the Direct Passions.
- Section X.: Of Curiosity, Or the Love of Truth.
- Book III: Of Morals
- Part I.: Of Virtue and Vice In General.
- Section I.: Moral Distinctions Not Deriv’d From Reason.
- Section II.: Moral Distinctions Deriv’d From a Moral Sense.
- Part II.: Of Justice and Injustice.
- Section I.: Justice, Whether a Natural Or Artificial Virtue?
- Section II.: Of the Origin of Justice and Property.
- Section III.: Of the Rules, Which Determine Property.
- Section IV.: Of the Transference of Property By Consent.
- Section V.: Of the Obligation of Promises.
- Section VI.: Some Farther Reflexions Concerning Justice and Injustice.
- Section VII.: Of the Origin of Government.
- Section VIII.: Of the Source of Allegiance.
- Section IX.: Of the Measures of Allegiance.
- Section X.: Of the Objects of Allegiance.
- Section XI.: Of the Laws of Nations.
- Section XII.: Of Chastity and Modesty.
- Part III.: Of the Other Virtues and Vices.
- Section I.: Of the Origin of the Natural Virtues and Vices.
- Section II.: Of Greatness of Mind.
- Section III.: Of Goodness and Benevolence.
- Section IV.: Of Natural Abilities.
- Section V.: Some Farther Reflexions Concerning the Natural Virtues.
- Section VI.: Conclusion of This Book.
The word Relation is commonly used in two senses considerably different from each other. Either for that quality, by which two ideas are connected together in the imagination, and the one naturally introduces the other, after the manner above-explained; or for that particular circumstance, in which, even upon the arbitrary union of two ideas in the fancy, we may think proper to compare them. In common language the former is always the sense, in which we use the word, relation; and ’tis only in philosophy, that we extend it to mean any particular subject of comparison, without a connecting principle. Thus distance will be allowed by philosophers to be a true relation, because we acquire an idea of it by the comparing of objects: But in a common way we say, that nothing can be more distant than such or such things from each other, nothing can have less relation; as if distance and relation were incompatible.
It may perhaps be esteemed an endless task to enumerate all those qualities, which make objects admit of comparison, and by which the ideas of philosophical relation are produced. But if we diligently consider them, we shall find that without difficulty they may be compriz’d under seven general heads, which may be considered as the sources of all philosophical relation.
1. The first is resemblance: And this is a relation, without which no philosophical relation can exist; since no objects will admit of comparison, but what have some degree of resemblance. But tho’ resemblance be necessary to all philosophical relation, it does not follow, that it always produces a connexion or association of ideas. When a quality becomes very general, and is common to a great many individuals, it leads not the mind directly to any one of them; but by presenting at once too great a choice, does thereby prevent the imagination from fixing on any single object.
2. Identity may be esteem’d a second species of relation. This relation I here consider as apply’d in its strictest sense to constant and unchangeable objects; without examining the nature and foundation of personal identity, which shall find its place afterwards. Of all relations the most universal is that of identity, being common to every being, whose existence has any duration.
3. After identity the most universal and comprehensive relations are those of Space and Time, which are the sources of an infinite number of comparisons, such as distant, contiguous, above, below, before, after, &c.
4. All those objects, which admit of quantity, or number, may be compar’d in that particular; which is another very fertile source of relation.
5. When any two objects possess the same quality in common, the degrees, in which they possess it, form a fifth species of relation. Thus of two objects, which are both heavy, the one may be either of greater, or less weight than with the other. Two colours, that are of the same kind, may yet be of different shades, and in that respect admit of comparison.
6. The relation of contrariety may at first sight be regarded as an exception to the rule, that no relation of any kind can subsist without some degree of resemblance. But let us consider, that no two ideas are in themselves contrary, except those of existence and non-existence, which are plainly resembling, as implying both of them an idea of the object; tho’ the latter excludes the object from all times and places, in which it is supposed not to exist.
7. All other objects, such as fire and water, heat, and cold, are only found to be contrary from experience, and from the contrariety of their causes or effects; which relation of cause and effect is a seventh philosophical relation, as well as a natural one. The resemblance implied in this relation, shall be explain’d afterwards.
It might naturally be expected, that I should join difference to the other relations. But that I consider rather as a negation of relation, than as any thing real or positive. Difference is of two kinds as oppos’d either to identity or resemblance. The first is called a difference of number; the other of kind.