This is a glossary of philosophical terms as they are generally used in the commonsense philosophical realism of Aristotle, Aquinas, and those in this tradition.
NOTE: In the case of qualified words, always look for the word or noun qualified. For example, in seeking for "Absolute Accident," look for "Accident, Absolute," etc.
A
Absolute. The unconditioned, the ultimate ground of all reality.
Absolute Statement, Fallacy of. A fallacy in which one argues from a statement which is generally true (absolute statement) to a specific case.
Absolute Supposition. The use of a term to designate merely the nature as such, without any reference to the individuals who are the bearers of this nature.
Absolutism, Epistemological. See Idealism, Absolute.
Abstract Idea. An idea which expresses a nature or determining attribute considered (by the mind) as separated from the subject in which it inheres.
Abstraction. A process in which the mind fixes its attention upon one or the other characteristic of a thing or upon one element common to many things, excluding others which are joined to it in the real order.
Abstractive Idea. An idea which is formed of objects by some means other than their immediate perception. Synonym: Mediate.
Accent, Fallacy of. A fallacy which arises from a false accent or false emphasis in speech. Synonym: Fallacy of Prosody.
Accident. A being whose nature it is to exist in another as in a subject.
Accident, Absolute. An accident which confers a real perfection upon its subject.
Accident, Extrinsic. An accident which does not affect the being of its subject, but modifies the subject's immediate surroundings.
Accident, Fallacy of. The fallacy which confuses the accidental and essential characteristics of a thing, so that what is affirmed of something as adventitious to a thing is also applied to the subject itself.
Accident, Intrinsic. An accident which affects the being of its subject in some manner.
Accident, Modal. The definite disposition or determination of an indifferent and determinable accidental entity in such a manner that it does not confer any positive and new entity upon the substance.
Accident, Relative. An accident that has its being in a subject only because of the bearing which one thing has to another.
Accident, Strictly Absolute. An accident which confers upon its subject some positive and new entity.
Accidental Definition. An explanation of a thing based on characteristics which are neither essential nor necessarily connected with the essence.
Acosmism. The doctrine which denies or doubts the validity of our experiential knowledge concerning the existence and reality of a material world; immaterialism.
Act. Any entity of whatever kind and nature which perfects and determines a thing in its being.
Act, Mixed. An act that in some form or other has an admixture of potentiality.
Act, Non-Pure. See Act, Mixed.
Act, Primary. An act that is the first in a series of acts.
Act, Pure. An act that is without the least admixture of potentiality.
Act, Secondary. An act that presupposes another act in a definite series, so that it proceeds from a primary act.
Action. The exercise or operation of an operative potency. The production of an effect.
Activity, Immanent. The activity through which a living being perfects itself and makes itself the goal for the acquired actuality or perfection.
Activity, Transient (Transeunt, Transitive). The activity which tends to change another object.
Activity, Vital. See Activity, Immanent.
Adversative. A proposition which consists of two propositions united in opposition to each other by conjunctions like "but," "although," "yet." Synonym: Discretive.
Affection. A relatively transient quality which produces, or results from, some accidental sensible alteration.
Agnosticism. The doctrine which denies the constitutional ability of the mind to know reality and concludes with the recognition of an intrinsically Unknowable.
Alteration. The change of a being from one qualitative state to another.
Amphiboly, Fallacy of. The ambiguous use of a phrase or of a complete sentence.
Analogous Term. A term which applies to unlike, but related, things.
Analogy. That reasoning process whereby the mind concludes from the known characteristics of one thing or group of things to the unknown characteristics of another thing or group of things because of a recognized resemblance existing between them.
Analysis. The scientific method which passes from the concrete to the abstract, from the complex to the simple, from the particular to the universal, from the application of a principle to the principle itself, from the phenomena to the underlying general law, from the effects to the cause. Synonym: A posteriori method.
Analytic Proposition. A proposition in which either the predicate is contained in the comprehension of the subject, or the subject is contained in the comprehension of the predicate. Synonyms: Necessary, essential, a priori.
Annihilation. The reduction of an existing being to nonexistence.
A Posteriori. Argument drawn from effects, consequents, or fact.
Appetency. The tendency of one thing toward another.
Appetency, Concupiscible. The propensity to enjoy a good.
Appetency, Irascible. The propensity to fight an evil.
Appetency, Rational. The will.
Appetency, Sensuous. The power in virtue of which a sentient being tends toward a consciously apprehended sensuous good and away from a consciously apprehended sensuous evil.
A Priori. Argument drawn from definitions formed or principles assumed, or which infers effects from causes previously known.
Argumentation. The verbal expression of a mediate inference.
Aristotelianism. The system of thought which in general follows the principles and teachings of Aristotle. Peripateticism.
Associationism. In the problem of necessary judgments, the doctrine which holds that the necessity of first principles is due to the law of associations as a form of mental compulsion.
Attention. The direction of the cognitive process toward an object, an activity, or a thought.
Attributes, Transcendental. The supreme modes necessarily connected with every being, which are different phases of the same fundamental being, but are not explicitly contained in its concept as such.
Augmentation. The change of a being from one quantitative state to another.
Axiological Ethics. Any ethics which makes the theory of obligation entirely dependent on the theory of value, by making the determination of the rightness of an action wholly dependent on a consideration of the value or goodness of something, e.g. the action itself, its motive, or its consequences, actual or probable. Opposed to deontological ethics.
B
Beauty. The attribute of a thing in virtue of which the thing pleases when perceived. A blending of the unity, truth, and goodness in a thing, characterized by completeness, proportion, and clarity of presentation in an intellectual-sensuous form, so as to produce a disinterested emotional pleasure in a rational perceiver.
Begging the Question. A fallacy in which the very conclusion (question) to be proved is, in some form or other, assumed to be true; or, one in which the conclusion is proved by a principle whose truth depends on the truth of the conclusion itself. Synonym: Petitio principii.
Behaviorism. The doctrine that psychology should restrict itself exclusively to observations and concepts relating to behavior.
Being. That which exists or can exist, the existible; whatever is not nothing.
Being, Absolute. A being which can be thought of or can exist without reference to another.
Being, Accidental. See Accident.
Being, Actual. Anything that really exists at the present moment in the physical or spiritual world.
Being, Contingent. A being whose nonexistence is possible.
Being, Contraction of. See Contraction of Being.
Being, Finite. A being whose reality is limited in perfection.
Being, Infinite. A being which has no limit in its entity or perfection.
Being, Logical. Anything that has objective being only in the mind.
Being, Necessary. A being whose nonexistence is impossible.
Being, Possible. Anything that does not actually exist, but is capable of existence.
Being, Real. Anything that has, or can have, existence independent of man's actual knowledge.
Being, Relative. A being which can be thought of or can exist only in reference to another.
Being, Substantial. See Substance.
C
Capacity, Natural. The proximate accidental principle of operation, toward which (operation) it is specifically directed.
Categorical Proposition. A proposition that makes a direct assertion of agreement or disagreement between subject and predicate.
Categorical Syllogism. A syllogism whose premises are categorical propositions.
Category. An ultimate and supreme mode of real being; a predicament.
Causal Definition. The explanation of a thing by means of its efficient or final causes.
Causal Proposition. A proposition that combines two statements in such a way that the one is given as the reason or cause of the other.
Causality, Principle of. The principle which states that whatever passes from a state of nonexistence into a state of existence must have an efficient cause for its existence.
Cause. That which in any way whatever exerts a positive influence in the production of a thing.
Efficient. That by which something is produced.
Equivocal. A cause which produces an effect dissimilar to itself in nature.
Cause, Final. That for the sake of which an efficient cause acts.
Cause, First. A cause whose causality is absolutely independent of any other cause or being, and on which all other causality depends.
Formal. That through which a thing is made to be what it is. Form.
Free. A cause which is not compelled to act, even though all the requisite conditions for action are present.
Instrumental. An efficient cause which produces an effect in virtue of the power of another cause.
Cause, Material. That out of which something becomes or is made. Matter.
Moral. A cause which inclines a free agent to act.