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WILLIAM FLEMING - 1890 - Table of contents

A - B - C - D - E - F - G - H- I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W  

Diccionario filosófico
Complete edition

Diccionario de Filosofía
Brief definition of the most important concepts of philosophy.


A Dictionary of English Philosophical Terms Francis Garden


Vocabulary of Philosophy, Psychological, Ethical, Metaphysical
William Fleming

Biografías y semblanzas Biographical references and lives of philosophers

Brief introduction to the thought of Ortega y Gasset

History of Philosophy Summaries

Historia de la Filosofía
Explanation of the thought of the great philosophers; summaries, exercises...

Historia de la Filosofía
Digital edition of the History of Philosophy by Jaime Balmes

Historia de la Filosofía
Digital edition of the History of Philosophy by Zeferino González

Vidas, opiniones y sentencias de los filósofos más ilustres
Complete digital edition of the work of Diogenes Laertius

Compendio de las vidas de los filósofos antiguos

A brief history of Greek Philosophy
B. C. Burt


A Short History of Philosophy






DEFINITION (definio, to mark out limits), "is used in Logic to signify an expression which explains any term so as to separate it from everything else, as a boundary separates fields" (Whately). A Definition is a categorical proposition, consisting of two parts or members, viz., a subject defined (membrum definitum) and the defining attributes of the subject, i.e., those by which it is distinguished from other things (membrum difiniens).

Logicians distinguish definitions into Nominal and Real. Those are called Nominal which explain merely the meaning of the term; and real, which explain the nature of the thing signified by the term. See Whately, Logic, bk. II. chap. V. sec. 6.

"By a real, in contrast to a verbal or nominal definition, the logicians do not intend 'the giving an adequate conception of the nature and essence of a thing;' that is, of a thing considered in itself, and apart from the conceptions of it already possessed. By verbal definition is meant the more accurate determination of the signification of a word; by real the more accurate determination of the contents of a notion. The one clears up the relation of words to notions; the other of notions to things. The substitution of notional for real would, perhaps, remove the ambiguity. But if we retain the term real, the aim of a verbal definition being to specify the thought denoted by the word, such definition ought to be called notional, on the principle on which the definition of a notion is called real; for this definition is the exposition of what things are comprehended in a thought" (Hamilton, Reid's Works, p. 691, note).

On the question whether logical Definition is real or nominal, various views are held. On the one hand, e.g., Mansel says:—"In the sense in which nominal and real definitions were distinguished by the scholastic logicians, logic is concerned with real, i.e., notional definitions only; to explain the meaning of words belongs to dictionaries or grammars" (Prolegom., Logic, p. 189). Whately, on the other hand, holds that "Logic is concerned with nominal definitions alone" (Logic, bk. II. ch. V. sec. 6). Mill also says—"The simplest and most correct notion of a definition is a proposition declaratory of the meaning of a word" (Logic, bk. I. ch. VIII. sec. 1). Accordingly he considers a Definition a "purely verbal" proposition.

"There is a real distinction between definitions of names and what are erroneously called definitions of things; but it is that the latter, along with the meaning of a name, covertly asserts a matter of fact. This covert assertion is not a definition, but a postulate.


The definition is a mere identical proposition, which gives information only about the use of language, and from which no conclusions respecting matters of fact can possibly be drawn. The accompanying postulate, on the other hand, affirms a fact which may lead to consequences of every degree of importance. It affirms the real existence of things, possessing the combination of attributes set forth in the definition, and this, if true, may be foundation sufficient to build a whole fabric of scientific truth" (Mill, Logic, bk. I. ch. VIII. sec. 6).

Real definitions are sometimes divided into essential and accidental. An essential definition states what are regarded as the constituent parts of the essence of that which is to be defined; and an accidental definition (or description) lays down what are regarded as circumstances belonging to it, viz., properties or accidents, such as causes, effects, &c. But in reality all Definition is essential, and hence is not to be confused with Description (q.v.). The Definition is an account of the essence of the notion or thing; hence it must contain the genus proximum and the differentia. For various other classifications of Definitions, see Ueberweg's System of Logic, p. 164, Lindsay's transl.

The Faults of Definition are thus enumerated by Ueberweg (Logic, p. 172, Lindsay's transl.):—(1) Too great width or narrowness; (2) Redundancy, or the mention of derivative determinations or properties, besides the essence; (3) Tautology, when the notion to be defined is repeated in the Definition; (4) Circulus in Definiendo, or the attempt to define a notion by means of those notions which presuppose it; (5) Definition by figurative expression or by mere negatives.

Aristotle, Topic, lib. VI.; Poster. Analyt., lib. II. ; Port Royal Logic, part I. ch. XII., XIII., XIV.; part II. ch. XVI.; Locke, Essay on Human Understanding, bk. III. ch. III. and IV.; Reid, Account of Aristotle's Logic, ch. II. sec. 4.



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