Inconsistent propositions, 76
Indefinite propositions, 65
Indefinite or infinite term, is a ne-
gative term which only marks an
object by exclusion from a class.
Indesignate propositions. See In-
definite propositions.

Indirect demonstration. See De-
monstration.

Indirect inference, method of,

192

Indirect reduction of the syllo-
gism, 146, 148-9.
Individual, what cannot be divided
without losing its name and distinc-
tive qualities, although generally
capable of physical division or par-
tition, which see.
Induction, 212

Inductive syllogism, 211, 214
Inference, defined, 81; immediate,
85-87; mediate, 126
Infima species, 100

Innate ideas, see a priori truths,208
Inseparable accident, 103
Instances, use of, 227
Intension and extension of terms,
37, 99, 208; law of relation, 40
Intensive syllogism, 159
Intention, first and second, a dis-
tinction between terms thus defined
by Hobbes :-" Of the first inten-
tion are the names of things, a man,
stone, &c.; of the second are the
names of names, and speeches, as
universal, particular, genus, species,
syllogism, and the like.' A term of
the second intention expresses the
mode in which the mind regards or
classifies those of the first intention.
Intermediate link, explanation
by, 267

Intuitive knowledge, 57.

Inversion of subject and predicate,
67
Irrelevant conclusion, fallacy of,
178

Judgment, 12

Language, the subject of logic, 10
Language, requisites of philoso-
phical, 290; three purposes of, 287
Laws of thought, 1, 117; of nature,
239

Leibnitz on Knowledge, 53
Lemma (λaußávw, to take or as-
sume), a proposition, a premise
granted; in geometry, a preliminary
proposition.

Limitation, conversion by, 82, 87
Logic, derivation of name, 6
Logical abacus, slate and machine,

199

Logomachy, 292

Lowest species, 100

Machine, the logical, 199
Major, term, 128; premise, 129
Many questions, fallacy of, 182
Material fallacies, 170, 176
Mathematical induction, 220
Matter of thought, 4; of proposi-
tions, 80

Matter is defined by J. S. Mill as
"the external cause to which we
ascribe our sensations," or as Per-
manent Possibility of Sensation.
Mediate inference, 126
Membra dividentia, the parts
into which a class is divided; the
constituent species of a genus.
Metaphor, 50

Metaphysical division, 108
Metaphysics (τὰ μετὰ τὰ Φυσικά),
the works of Aristotle which fol-
lowed or were studied after his
Physics. First Philosophy, or the
so-called science of things in their
own nature; ontology or the science
of Being.

Method (μέθοδος, μετά and ὁδός,
way), mode, way or instrument of
accomplishing an end.

Method, the fourth part of logic,
15, 201; Pascal on, 114; Descartes'
Discourse on, 116; of indirect infer-
ence, 192

Methods of Induction, Agreement,
240; Difference, 242; of Experi-
ment, 243: Joint Method, 245;
Residues, 252; Concomitant Varia-
tions, 249
Metonymy(μerá, and ovoμa,name),
grammatical name for the transfer
of meaning of a word to a closely
connected thing, as when we speak
of the church, meaning the people in
it. See Transfer of meaning.
Middle Term, 126, 128

Mill, J. S., on Connotative terms,
41; on Induction, 214; on Analogy
and Induction, 227; on Observation,
235; on Terminology and Nomen-
clature, 294

Minor term, 128; premise, 129
Mnemonic verses, Barbara, &c.,
144

Modal proposition, 69, 91

Modus, ponens, 161; tollens, 162
Modus, ponendo tollens, 166; tol-
lendo ponens, 166

Moods of the syllogism, 136; ac-
cording to Hamilton, 188

Name, or term, 17

Natural Classification, 280
Natural Kinds, 294
Necessary matter, 80

Necessity (ne, not; and cesso, to
cease), that which always is and can-
not but be.

Negation, conversion by, 83
Negative, terms, 22; propositions,
63, 83; premises, fallacy of, 133-4
Newton's experiments, 253, 259
Nomenclature, 293
Nominal definitions, 112
Nominalists, 13

Non causa pro causa, 181
Non sequitur, 181
Notion (nosco, to know), the action
of apprehending or taking note of
the various qualities of an object; or
more commonly the result of that
action. See Idea, Concept.
Notiora naturæ, 204,
Novum Organum, first aphor-
isms of, 229
Numerically definite syllogism,

190

Object of verb, 93

Objective, that which belongs to
the object of thought, the non-ego;
opposed to Subjective, which see.
Obscure knowledge, 54
Observation, 231, 235
Occasion of an event, the proximate
cause, or last condition which is
requisite to bring other causes into
action; 239
Opposite terms, 24, 119
Opposition of propositions, 78
Organon (õpyavov, Latin Organum,

Instrument), a name for Aristotle's
logical treatises, first generally used
in the 15th century, implying that
they may be regarded as an instru-
ment to assist the mind. The name
was adopted by Bacon for his Novum
Organum.

Paradox (Tapá, dóğa, contrary to
opinion), an assertion contrary to
common opinion, and which may or
may not prove true; often wrongly
used to mean what is self-contradic-
tory and absurd.
Paralogism (rapaλoyisoμai, to rea-
son wrongly), a purely logical fallacy,
or breach of the rules of deductive
logic.

Parity of reasoning, an expression
used to denote that when one case
has been demonstrated, other simi-
lar cases can be demonstrated by a
like course of reasoning.
Paronymous words, see Conju
gate words.

Particular propositions, 63-6,72,79
Particular premises, fallacy of, 135,

145

Perfect knowledge, characters
of, 53

Periodic changes, 250

Peripatetic Philosophy (EρLTATÓW,
to walk about), the name usually
given to the doctrines of Aristotle
and his followers, who are said to
have carried on their studies and
discussions while walking about the
halls and promenades of the Lyceum.
Petitio Principii, 179
Phenomenon, 240

Philosophical language, re-
quisites of, 290

Physical definition assigns the
parts into which a thing may be
separated by partition or physical
division.

Plurative propositions, 191
Polylemma, an argument of the
same form as a dilemma, but in which
there are more than two alternatives,
Porphyry, tree of, 103

(prædicamenta,

what can be predicated), see Cate-
gories.
Predicate, 62, 88, 92; quantified,
183

Premise, or Premiss, 15, 127
Primary Laws of Thought, 117
Principle (principium, beginning),
the first source of anything; some-
times specially used to mean the
major premise of a syllogism.
Privative conception, inference
by, 85

Privative terms, 24

Probability, quantity or degree of
belief, or more truly, quantity of in-
formation concerning an uncertain
event, measured by the ratio of the
number of cases favourable to the
event to the total number of cases
which are possible.
Probability, of propositions, 70; of
inductions, 223

Problem (poßλnua, that which is
thrown down), an assertion put for-
ward for proof or disproof.
Proof, the assigning a reason or ar-
gument for the support of a given
proposition.

Proper names, 18

Property or proprium, 41, 102, 109
Propositions, 10, 16; several kinds

of, 60; affirmative and negative, 63;
categorical, 63; conditional, 62, 160;
disjunctive, 62, 160; essential or ex-
plicative, 68; exclusive, exceptive,
68; hypothetical, 62, 162; indefinite
or indesignate, 65; modal, 69, 91;
opposition of, 78; particular, 63-6,
72, 79; pure, 69; plurative, 191; ir-
regular, 67; quality and quantity of,
63

Frosyllogism, 155
Froximate genus, 108

Quantification of predicate, 183
Quantity of propositions, 63; ques-
tions of quantity, 120

Quaternio terminorum, 170

Ramean tree, see Tree of Por
phyry.
Ratiocination, a name equivalent
to Syllogism or Deduction, adopted
by J. S. Mill.
Realism, 13.

Reason (ratio, from reor, to think),
a term of wide and ambiguous mean-
ing; it has sometimes been specially
used to denote the minor premise of
a syllogism.

Reasoning, or discourse, 15
Record, language as instrument of,
289
Reductio ad absurdum or ad
impossibile, an indirect demonstra-
tion founded upon the impossibility
of a contradictory supposition, 146
Reduction of the syllogistic figures,
145; of hypothetical to categorical
syllogisms, 163-5

Relation (relatum, past participle
of refero, to bear back), any con-
nection in thought or fact between
two things, 21
Relative terms, 25
Residual phenomena, 254
Residues, method of, 252
Rules of the syllogism, 127

Scholastic Philosophy, a ge-
neral name for the systems of philo-
sophy taught during the middle ages
from the 9th to the 16th century,
flourishing chiefly in the 13th and
14th centuries. The subject was
chiefly the logic of Aristotle, varied
with theology, metaphysics, gram-
mar, or rhetoric.

Second Intention, see Intention.
Secundi adjacentis, of the se-
cond adjacent, an expression in in-
correct Latin, applied to a gram-
matical sentence or proposition con-
taining only two parts, the subject
and verb, without a distinct copula.
Self-contradictory terms, 193
Semilogical fallacies, 171
Sentence, grammatical, 61, 89
Separable accident, 103

Significates of a term are things
denoted or signified by it.

Similars, substitution of, 124, 200
Simple, apprehension, 11; conver-
sion, 82, 184

Singular, terms, 18; propositions,64
Sophism (σόφισμα, from σοφία, wis-
dom), a false argument; the name
often implies that a false argument
is consciously used for deception.
Sorites, 156

Specialization of names, 45, 48
Species, in logic, 98; in natural
history, 101

Subaltern, propositions, 77; genera
and species, 100

Subalternans, subaltern-
ates, 77

Subcontrary Propositions, 77
Subject of a proposition, 62, 92
Subjective, that which belongs to
the thinking subject, the ego, or
mind engaged in thought; opposed
to objective, which see.
Subordinate propositions, 91
Substance (sub, under; stans from
stare, to stand), that which underlies
and bears phenomena or attributes;
strictly speaking it is either mind or
matter, but it is more commonly
used in the material sense.

Substitution of similars, 124, 200
Subsumption (sub, under; sumo,
to take or put), a name used by Sir
W. Hamilton for the minor premise
of a syllogism, because it brings or
subsumes a special case under the
rule expressed in the major premise
or sumption.

Subsumption of a law is Mr
Mill's expression for the third mode
of explaining a law by shewing it to
be a particular case of a more ge-
neral law, 268

Sufficient Reason, Principle or
Law of, 125
Sui generis, 101
Summum genus, 100
Sumption (sumo, to take), Sir W.
Hamilton's name for the major pre-
mise of a syllogism.
Supposition, 270

Syllogism, 10, 127; inductive, 211,

214

Symbolical knowledge, 57

Syncategorematic words, 18
Synthesis, 205

Synthetic syllogism, a syllo-
gism in which the conclusion stands
last; see Analytic syllogism.
System, (σύστημα, from συνίστημι,
to put together), a connected body of
knowledge.

Tacit premise, 153
Tautologous propositions, 69
Tendency, 266
Terminology, 292
Terms, 10, 16, 17

Tertii adjacentis, of the third
adjacent, an expression in incorrect
Latin, applied to a grammatical sen-
tence or proposition in which the
subject, copula and predicate, are
all distinctly stated.

Theory (ewpía, contemplation),
knowledge of principles, as opposed
to practice; ambiguously used, see

p.

This (θέσις, from τίθημι, to place),

an assertion or proposition which is
put forth to be proved or supported
by arguments.

Thoughts on things, the object of
logic, 10

Totum divisum, a class or notion
which is divided into parts by a
difference.

Traduction, 212

Transfer of meaning of terms, 32
Tree of Porphyry, 103
Trilemma, an argument resem-
bling a dilemma, but in which there
are three alternatives.
Truisms, 69

Truth, conformity of our knowledge
with the things known.

Ultra-total distribution, 191
Uniformity of nature, 217
Universal propositions, 63,
66; affirmative, 71; negative, 73
Univocal terms, 29

Variations, method of, 249: pe-
riodic, 250

Verb, 88

Weakened conclusion, 140
Worse relation (Hamilton), 190