See also argumentation; mathematics; philosophy; thinking; truth and error.

a posteriori
the process of reasoning from effect to cause, based upon observation.

**apriorism**
**1.** the method of

a priori reasoning, i.e., deductive reasoning, from cause to effect or from the general to the particular.

**2.** an

a priori principle.

Barbara
a mnemonic word to represent a syllogistic argument in the first figure, in which there are two universal affirmative premises and a universal affirmative conclusion.

**Barmalip, Bramantip**
a mnemonic word to represent a syllogistic argument in the fourth figure, in which there are two universal affirmative premises and a particular affirmative conclusion.

**Baroco**
a mnemonic word to represent a syllogistic argument in the second figure, in which there is one universal affirmative and one particular negative premise and a particular negative conclusion.

**Bocardo**
a mnemonic word to represent a syllogistic argument in the third figure, in which there is one particular negative and one universal affirmative premise and a particular negative conclusion.

**Camestres**
a mnemonic word to represent a syllogistic argument in the second figure, in which there is one universal affirmative and one universal negative premise and a universal negative conclusion.

**Celarent**
a mnemonic word to represent a syllogistic argument in the first figure, in which there is one universal negative and one universal affirmative premise and a universal negative conclusion.

**Cesare**
a mnemonic word to represent a syllogistic argument in the second figure, in which there is one universal negative and one universal affirmative premise and a universal negative conclusion.

**Darapti**
a mnemonic word to represent a syllogistic argument in the third figure, in which there are two universal affirmative premises and a particular affirmative conclusion.

**Darii**
a mnemonic word to represent a syllogistic argument in the first figure, in which there is one universal affirmative and one particular affirmative premise and a particular affirmative conclusion.

**Datisi**
a mnemonic word to represent a syllogistic argument in the third figure, in which there is one universal affirmative and one particular affirmative premise and a particular affirmative conclusion.

definiendum
**1.** an expression that has to be defined in terms of a previously defined expression.

**2.** anything that has to be defined. —

**definienda**,

n., pl.

**Dimaris**
Dimatis.

**Dimatis**
a mnemonic word to represent a syllogistic argument in the fourth figure, in which there is one universal affirmative and one affirmative premise and a particular affirmative conclusion. Also called

**Dimaris**.

**Disamis**
a mnemonic word to represent a syllogistic argument in the third figure, in which there is one particular affirmative and one universal affirmative premise and a particular affirmative conclusion.

elenchus
a syllogistic argument that refutes a proposition by proving the direct opposite of its conclusion. —

**elenchic, elenctic**,

adj.

**epicheirema**
a syllogism in which the truth of one of the premises is confirmed by an annexed proposition

(prosyllogism), thus resulting in the formation of a compound argument. See also

**prosyllogism**.

equipollence, equipollency
equality between two or more propositions, as when two propositions have the same meaning but are expressed differently. See also

agreement.

**Felapton**
a mnemonic word to represent a syllogistic argument in the third figure, in which there is one universal negative and one universal affirmative premise and a particular negative conclusion.

**Ferio**
a mnemonic word to represent a syllogistic argument in the first figure, in which there is one universal negative and one particular affirmative premise and a particular negative conclusion.

**Feriso**
a mnemonic word to represent a syllogistic argument in the third figure, in which there is one universal negative and one particular affirmative premise and a particular negative conclusion. Also

**Ferison**.

**Ferison**
Feriso.

**Fesapo**
a mnemonic word to represent a syllogistic argument in the fourth figure, in which there is one universal negative and one universal affirmative premise and a particular negative conclusion.

**Festino**
a mnemonic word to represent a syllogistic argument in the second figure, in which there is one universal negative and one particular affirmative premise and a particular negative conclusion.

**Fresison**
a mnemonic word to represent a syllogistic argument in the fourth figure, in which there is one universal negative and one particular affirmative premise and a particular negative conclusion.

**metalogic**
the metaphysics or metaphysical aspects of logic. —

**metalogical**,

adj.

methodology
a division of logic devoted to the application of reasoning to science and philosophy. See also

classification;

order and disorder. —

**methodological**,

adj.

**polylemma**
a multiple dilemma or one with many equally unacceptable alternatives; a difficult predicament.

**prosyllogism**
a syllogism connected with another in such a way that the conclusion of the first is the premise of the one following.

schematism
the form or character of a syllogism.

sorites
an elliptical series of syllogism, in which the premises are so arranged that the predicate of the first is the subject of the next, continuing thus until the subject of the first is united with the predicate of the last. —

**soritical, soritic**,

adj.

syllogism
a form of reasoning in which two propositions or premises are stated and a logical conclusion is drawn from them. Each premise has the subject-predicate form, and each shares a common element called the

middle term.

**syntheticism**
the principles or practice of synthesis or synthetic methods or techniques, i.e., the process of deductive reasoning, as from cause to effect, from the simple elements to the complex whole, etc.