The Lives and Opinions of Eminent Philosophers Diogenes Laërtius (first ebook reader .TXT) 📖

for instance, some derive them from a king; and then it will be necessary to humor him. Some from friendship; and then friendship will become a thing to be bought with a price. Some from wisdom; and then wisdom will become mercenary;” and these are the accusations which he brings.

But since he has written many books of high reputation, it has seemed good to me to give a catalog of them, classifying them according to their subjects. They are the following:

Books on Logic; Propositions; Logical Questions; a book of the Contemplations of the Philosopher; six books of Dialectic Terms addressed to Metrodorus; one on the Technical Terms used in Dialectics, addressed to Zeno; one called the Art of Dialectics, addressed to Aristagoras; four books of Probable Conjunctive Reasons, addressed to Dioscorides.

The first set of treatises on the Logical Topics, which concern things, contains: one essay on Propositions; one on those Propositions which are not simple; two on the Copulative Propositions, addressed to Athenades; three on Positive Propositions, addressed to Aristagoras; one on Definite Propositions, addressed to Athenodorus; one on Privative Propositions, addressed to Thearus; three on the Best Propositions, addressed to Dion; four on the Differences between Indefinite Propositions; two on those Propositions which are enunciated with a reference to time; two on Perfect Propositions.

The second set contains, one essay on a Disjunctive True Propositions, addressed to Gorgippides; four on a Conjunctive True Proposition, also addressed to Gorgippides; one called, the Sect, addressed to Gorgippides; one on the argument of Consequents; one on questions touched upon in the three preceding treatises, and now reexamined, this also is addressed to Gorgippides; one on what is Possible, addressed to Clitus; one on the treatise of Philo, on Signification; one on what it is that Falsehood consists in.

The third set contains, two treatises on Imperative Propositions; two on Interrogation; four on Examination; an epitome of the subject of Interrogation and Examination; four treatises on Answer; an abridgment on Answer; two essays on Investigation.

The fourth set contains ten books on Categorems, addressed to Metrodorus; one treatise on what is Direct and Indirect, addressed to Philarchus; one on Conjunctions, addressed to Apollonides; four on Categorems, addressed to Pasylus.

The fifth set contains, one treatise on the Five Cases; one on Things defined according to the Subject; two on Enunciation, addressed to Stesagoras; two on Appellative Nouns.

The next class of his writings refers to rules of Logic, with reference to words, and speech which consists of words.

The first set of these contains, six treatises on Singular and Plural Enunciations; five on Words, addressed to Sosigenes and Alexander; four on the Inequality of Words, addressed to Dion; three on the Sorites which refer to Words; one on Solecisms in the Use of Words, addressed to Dionysius; one entitled Discourses, Contrary to Customs; one entitled Diction, and addressed to Dionysius.

The second set contains, five treatises on the Elements of Speech and of Phrases; four on the Arrangement of Phrases; three on the Arrangement, and on the Elements of Phrases, addressed to Philip; one on the Elements of Discourse, addressed to Nicias; one on Correlatives.

The third set contains, two treatises against those who do not admit Division; four on Ambiguous Expressions, addressed to Apollos; one, Ambiguity in Modes; two on the Ambiguous Use of Figures, in Conjunctive Propositions; two on the essay on Ambiguous Expressions, by Panthoides; five on the Introduction to the Ambiguous Expressions; one, being an abridgment of the Ambiguous Expressions, addressed to Epicrates; and a collection of instances to serve as an Introduction to the Ambiguous Expressions, in two books.

The next class is on the subject of that part of logic which is conversant about reasonings and modes.

The first set of works in this class contains The Art of Reasoning and of Modes, in five books, addressed to Dioscorides; a treatise on Reasoning, in three books; one on the Structure of Modes, addressed to Stesagoras, in five books; a comparison of the Elements of Modes; a treatise on Reciprocal and Conjunctive Reasonings; an essay to Agathon, called also an essay on Problems, which follow one another; a treatise, proving that Syllogistic Propositions suppose one or more other terms; one on Conclusions, addressed to Aristagoras; one essay, proving that the same reasoning can affect several figures; one against those who deny that the same reasoning can be expressed by syllogism, and without syllogism, in two books; three treatises against those who attack the resolution of Syllogisms; one on the treatise on Modes, by Philo, addressed to Timostratus; two treatises on Logic, in one volume, addressed to Timocrates and Philomathes; one volume of questions on Reasonings and Modes.

The second set contains one book of Conclusive Reasonings, addressed to Zeno; one on Primary Syllogisms which are not demonstrative; one on the resolution of Syllogisms; one, in two books, on Captious Reasonings, addressed to Pasylus; one book of Considerations on Syllogisms; one book of Introductory Syllogisms, addressed to Zeno; three of Introductory Modes, addressed also to Zeno; five of False Figures of Syllogism; one of a Syllogistic Method, for the resolution of arguments which are not demonstrative; one of Researches into the Modes, addressed to Zeno and Philomathes (but this appears to be an erroneous title).

The third set contains one essay on Incidental Reasonings, addressed to Athenades (this again is an incorrect title); three books of Incidental Discourses on the Medium (another incorrect title); one essay on the Disjunctive Reasons of Aminias.

The fourth set contains a treatise on Hypothesis, in three books, addressed to Meleager; a book of hypothetical reasonings on the Laws, addressed also to Meleager; two books of hypothetical reasoning to serve as an Introduction; two books of hypothetical reasonings on Theorems; a treatise in two books, being a resolution of the Hypothetical Reasonings of Hedylus; an essay, in three books, being a resolution of the Hypothetical Reasonings of Alexander (this is an incorrect title); two books of Expositions, addressed to Leodamas.

The fifth set contains an introduction to Fallacy, addressed