Abstraction: An act of the mind by which the intellect grasps the essence, or whatness, of a thing, prescinding from the object’s accidental or individual characteristics.
Accident: Any of the nine modes by which a substance is determined in its being. It is a mode of being that exists in, and only in, a finite substance. It cannot exist of itself, but must inexist. Once you name a substance and define it, anything else you predicate of it, using the verb “to be,” is an accident.
Act: “To do” or “to make;” to move toward the achievement of an end; to engage a potency; to bring into being. It is the movement or work of an efficient cause.
Agnosticism: A philosophy that denies the possibility of certitudes.
Angel: A finite and immaterial creature; an incorporeal substance having the powers of knowledge and desire, wholly personal unto itself, unique as to its own individual identity or person, and contingent upon God its Creator.
Animal: A creature of a sentient nature.
Art: The skillful application of correct knowledge in the order of making. It is a habit residing in the soul of the artist which is ordered toward making rather than mere doing.
Attribute: A perfection or quality inherent in the very nature of a thing.
Beauty: That quality which gives pleasure upon being seen by the eye of the body or the intellect. Metaphysically speaking, beauty consists in a unity among diversity. In God there exists Infinite Beauty in the Oneness of the Three Eternal Persons. This Beauty is the Object of the Beatific Vision.
Being: The term cannot be defined because it is common to all existing realities. What we understand by the concept is that which has existence. Ontology studies “being” in all modes of existence. Metaphysics studies “being” as transcendental, that is, abstracted from individual existences, being as being.
Cause: The principle from which the existence of a thing proceeds and upon which it depends; a principle that directly instigates a change in something. As with the term “being,” there are varied categories of causality. The primary sense, here given, is that of an efficient or active cause; the agent.
Cognition: The act of knowing, acquiring knowledge, whether through the intellect via intuition (angels), or through the intellect via the inner and outer senses (man), or, in its lowest form, purely sensual apprehension (animals).
Concept: Or Idea: It is the expression by the mind or in the mind through which we understand or conceive a thing.
Contingent: That type of being which either can be or not be; a being that can change; a dependent being.
Cosmology: The study of final causes, reasons (design), and ends in the material universe. Or, the study of the essential natures of contingent material beings, individually and concordantly, as an ordered reality.
Deism: Belief in God that is derived solely by reason. It admits of a Supreme Being that posited order in a pre-existing chaos, but denies that He concerns Himself providentially in man’s affairs. As a clock is made and set to operate by the craftsman, so did God, in this view, fashion the universe to run mechanically and, relative to His presence, at a distance.
Determinism: Denies freedom of the will in causality. According to this fateful school of thought, all effects are necessary, and not contingent. It is a cosmological application of Deism.
Disposition: The quality or state of a substance to receive a form easily and naturally. St. Thomas speaks of matter’s disposition to receive a form. As a quality of the spiritual faculties the term can only be used in its less philosophical sense of inclination. In distinction to habit, however, disposition is a quality in inanimate as well as animate substances. (See Habit for further distinction.)
Empirical: That which depends on personal experience or scientific and observable experiments.
End: The real or apparent good for the sake of which an action is undertaken; purpose; goal.
Ens Mobile: A being capable of change; after God, Who is immutable in His very Essence, all beings and substances are ens mobile.
Epistemology: The study of human knowledge as derived from the senses. It is also called Major Logic. In distinction to Minor Logic, whose object is the art of correct reasoning, epistemology is the study of reason itself and abstraction.
Essence: That by which a thing is that which it is, or that by which it is constituted in a species; the whatness of a thing. Essence answers the question: What is it?
Ethics: The study of human acts, either what man does or what he ought to do. Ethics seeks to know the proper end of human acts, the true good, as it can be known by reason. It is also called Moral Philosophy.
Existence: Like the concept being, existence is incapable of a real definition because there is nothing in the understanding of the term that can be categorized by some composition. We can say that existence is a perfection, indeed the ultimate perfection of an essence. In all created things existence is the act of essence; whatever a thing is, if it is in act, actual, it exists and therefore has being.
Existentialism: A modern view of reality that denies the existence of essences. Things that exist are what they appear to be only. The being and the appearance of a thing are identical. There are no essences, only existing things. Each thing is what it proclaims itself to be. Man is whatever he makes of himself.
Faculty: A power of the soul enabling a living substance to operate according to its nature by doing or making. It is a vital capacity belonging to a living substance. Ultimately, it is the immediate and proximate principle of vital operation.
Form (Substantial): The principle or cause of a thing’s intelligibility. It is not to be confused with its common sense of shape. Nor ought one to think of form as something pre-existing, but rather, as a concept that is the determining cause or principle which confers the essence or whatness upon a substance. It determines matter to be this and not that. In man the form is the soul. In spiritual creatures it can exist outside of matter.
Genus: It is the highest category. Genus comprises all the common constituent notes of the individual notes that characterize the members of the more exclusive classes of reality known as species. The genus animal includes the species man as well as brutes. Brutes is a species of a genus, but it is also a genus to other species that all share its common individual notes. Man, however, is not a genus, for there are no other beings that share his constituent notes.
Good: That which is desirable. The object of the will. The will, by nature, desires the good. Even if the will chooses evil, it must desire it as a good. It must impose this deception upon the object in order for that object to be desirable. Also, ontologically, that which perfects a nature is a true good.
Grammar: The science or art of correct writing. As an art this habit resides in the intellect. Its end is the conformity of one mind with other minds through the medium of the written word. Grammar should be at the service of logic.
Habit: A permanent quality of the soul through which a person, by repetition, has acquired the easy ability to perform an act. In itself, a habit or disposition is neutral. It can be ordered by the will toward what is morally good or bad.
Happiness: Contentment in the possession of the good.
Hylomorphism: The Aristotelian explanation of material reality. All matter has a double composition of prime matter and substantial form, the former being related to the latter by way of potency to act. Neither exists on its own. What exists is the composite, i.e., informed matter. Matter, having been actualized and determined by a substantial form to be this thing, now exists really in the composite. Informed matter is called secondary matter.
Idea (Concept): That expression by the mind and in the mind by which the intellectual soul, through the medium of the senses, understands or conceives something. Also, a plan, an exemplary or formal cause of an act. The will moves the mind to adopt a pattern (idea) which is the cause (formal) of purposive action. (See Concept.)
Idealism: In its Platonic sense, it is the positing of real existence to universals, as subsisting essences, outside of the individual substances themselves. In its modern usage, idealism denies the intelligibility of objective things existing outside the mind (Descartes, Berkeley, et. al.). The absolute idealist denies even the existence of objective reality. Being immaterial, the mind, so they erroneously allege, cannot have any real knowledge of material things. Hence, their fallacious axiom, “to be is to be perceived” (esse est percipi).
Immanent Action: Change or movement of any kind beginning and ending within the substance itself. A vital activity.
Intellect: A spiritual faculty through which, by the power of cognition, a mind grasps the essences of things as absolutes rather than as relative things. Through this power one perceives the relations themselves of things to other things, of effects to causes, means to end. By this faculty one can formulate universal concepts, one can judge and infer, and by inference come to understand even those things which in no way fall under the sensitive cognition — as first cause to ultimate end and the relation of human acts to the same final end.
Judgment: The act of the intellect by which it composes or divides by affirming or denying. In constructing propositions or sentences, this act is performed whenever the intellect perceives the befittingness or the discrepancy of two concepts with each other.
Justice: A habit of the soul by which someone with a constant and abiding will renders to another his just due. One of the four cardinal virtues. As the other cardinal virtues consider the good itself of the one in which they operate, justice considers the good of another, either that which is owed to another or ordained to his utility as due to him, i.e., as that which should be his. In the highest sense, it is rendering to God His due, that is, by conforming ourselves to His Will. This is done through grace. The state of grace is called justice in the Scriptures.
Knowledge: The fruit of the union of mind and reality. The informing of the mind with intelligibles, or forms, or essences of things. Cognition. Possession by the mind of any of the forms of data from historical to empirical, from universals to the finite comprehension of the unveiled God to the blessed in heaven.
Liberal Arts: Those sciences which do not have matter, per se, for their objective content. They are the sciences which man, as man, ought to be versed in, as opposed to those sciences which constitute specialization.
Life: The immanent active power of an animate material creature, of a human soul in the separated state, or of a pure spirit. The power of self-movement; intrinsic motion — that is, the power of a thing, within itself, to initiate a change or movement, and end it, independent of any other created cause.
Logic: The science and art of correct reasoning. An art that directs the act itself of reason, through which the possessor proceeds in reasoning with order, facility and without error.
Man: An intelligent creature of God composed of matter and informed by a rational and immortal soul as its principle of life.
Materialism: Denial of immaterial and all spiritual reality; a deduction of atheism.
Matter: That ultimate substantial reality which is known by its accidents of quantity (weight), quality, extension (shape), visibility (color), and utility. Matter is whatever its substantial form determines it to be, i.e., a grain of sand or a human body.
Mathematics: A science that utilizes quantity in the abstract, through number and measurement, for the purpose of establishing equational relations in that specific field. Abstracting from the things that are numbered, measured or equated, Mathematics studies quantity in its threefold relations: 1) As discreet or enumerable, the subject of Arithmetic 2) As equational, the subject of Algebra 3) As continuous, the subject of Geometry.
Metaphysics: The science of the transcendentals, which are the ultimate attributes of all that exists or has being. It studies being as one, true, good, and beautiful. General Metaphysics is also called Ontology. (See Ontology) Special Metaphysics includes the study of all immaterial reality as we examine it in Psychology, Cosmology and Natural Theology, or Theodicy.
Moderate Realism: An Aristotelian explanation of the nature of universals, or ideas, in opposition to both the exaggerated idealism of Plato and the denial of universals by nominalists. Saint Thomas championed the balanced middle view of Aristotle which posited the real existence of universal ideas, not subsisting on their own, but in the individual concrete substances which have real subsistence.
Motion: In scholastic usage motion extends to any form of change, any passage from potency to act, e.g., ignorance to knowledge. Obviously, there is also the common sense: a change of place, locomotion.
Music: A fine art. It is a concordant or harmonious, and simultaneous arrangement of sounds. Sound is the object of hearing. Music uses the brushes of instruments to compose beauty on a canvas for the ear.
Natural Order: The divine plan as executed in creation. The economy of God in His physical laws and in the moral law implanted in the mind of every man.
Naturalism: Denies the supernatural in the order of the universe. Consequently, man is freed of any other moral obligation than that which imposes itself for the harmonious interaction between members of human society. Denies original sin.
Nature: The essence of a thing considered as the principle of what it can do, or what can be done to it. (See Essence.) Nature is the operative manifestation of essence.
Necessary: That which must be, or cannot not be, as opposed to contingent.
Nominalism: Rejection of universals as anything more than figments of each person’s imagination; man knows things commonly only because of the accident of accepted language; universals are nothing more than words.
Normative: That which establishes rules and laws by comparison of facts.
Objective: In philosophy, it is the emphasizing of the concrete reality as it is itself, outside the mind, not as analyzed in the mind.
One: That which is undivided in itself and divided from everything else.
Ontology: That branch of the science of metaphysics that studies immaterial being under the aspect of being, not specifically, but generally. What is immaterial being? What can we say about it?
Order: The correct arrangement of means to end.
Pantheism: Any systematic view of reality that removes the infinite distinction between God and creation. Pantheists equate God with all being univocally, that is, in such a way that everything that shares in being is a greater or lesser divine emanation.
Passion: An accident by which a subject is established in act by receiving the effect of an agent or cause. Potency to be moved in any way, that is, to be acted upon. (See Act)
Person: The owner of the spiritual faculties; the ultimate responsible agent; possessor of the power to reflect, to self-recognize, to be responsible. All spiritual beings are persons. Simplifying the scholastic definition, we can say that person is the complete individual and incommunicable substance possessing a rational or intellectual nature.
Phantasm: The mental picture or image of a material thing. This is not the same as idea or universal. The idea is the mind’s understanding of, or abstraction of, the form of a substance; the phantasm is the sensual reproduction. Phantasm is to the sensual nature what idea is to the intellectual mind.
Philosophia Perennis: The wisdom that has endured the centuries because of the correctness of its content; true philosophy, perennial; that natural wisdom of principles that has reflected some of the rays of divine light or truth, and withstood the errors that produce darkness.
Philosophy: The love of wisdom. In application, it is the study of the first principles and the ultimate causes of all knowable reality.
Physics: The study of material reality as ens mobile, beings of change. Whereas the experimental science of Physics studies conclusions drawn from the particular data observed in material things, the philosophic study of Physics, in its consideration of ens mobile —the material world as it appears to the senses — abstracts from this singular material thing or this individual condition to examine the mutability of the material world in general.
Potency: This concept can only have meaning in relation to act. It essentially and necessarily is identified with an act because it is the capacity in a thing to be actual. Any unachieved but achievable perfection of any kind in any kind of being.
Power: Potency to perform particular acts, to do or to make; potency considered in its active sense. A faculty in the nature of a being that is permanent and ordered to a specific function.
Principle: That from which anything, in any way or manner, proceeds. The starting point of any operation; not always the cause, though oftentimes it is. A dot is the principle of a line, but not the cause. Principle is a more universal concept than cause.
Property: An attribute of a thing that necessarily results from its essence, but is not so fundamental to it as to belong to its very definition; that which is unique to, but not essential to. The ability to laugh is proper to man, but not essential for man to be man.
Quality: An intrinsic accident that modifies or determines a substance in itself. It completes or perfects a substance in its being or operation. It answers the question: “What kind of a substance is this?” Or, “How is this substance in itself?”
Quantity: The accident of a material substance by which it is extended into space. This accident does not determine a substance in itself absolutely, but extrinsically, i.e., in relation to a boundary or to something adjacent to it. Quantity can be measured, or weighed, counted or circumscribed. It answers the questions: “How much? or How many?”
Reason: Considered as a power, as the mode of intellectualization in this mortal life; it is the mental process of equating two or more judgments in order to form a conclusion. It is a deliberate power that is engaged whenever we formulate a conclusion or opinion by moving from particular judgments to general ones (induction) or from general judgments to particular ones (deduction).
Realism (Exaggerated): (See Moderate Realism.) Unmodified, realism simply affirms the existence of universal essences. Having posited this as a certainty, the advocates of exaggerated realism part company from the moderate realism of the scholastics by maintaining the actual existence of essences or universals outside of the individual substance. In their view, all trees are an imperfect reflection of the essential and exemplary universal tree that has actual real, though, of course, immaterial existence. What exists really, for Plato, is the universal tree. Plato posits the existence of this ideal tree in the mind of the Logos, the word of God. Saint Augustine gave this same philosophy a Christian interpretation.
Rhetoric: The science and art of correct speaking. Its object is the conformity of two or more minds with the mind of the speaking artist.
Scholasticism: (See Philosophia Perennis.) Rooted in the natural wisdom of Aristotle and the theological teaching of the Fathers of the Church — especially that of Saint Augustine — it was that system of philosophy advanced in the Christian schools of the Middle Ages. It achieved its greatest heights under the direction of Saints Albert the Great and Thomas Aquinas. A second period of revival manifested itself in the sixteenth and seventeenth centuries wherein philosophy was rigorously subservient to the interests of Catholic orthodoxy. In short, scholasticism is that educational system that utilizes all the natural wisdom that survived antiquity, adorning it with the higher supernatural wisdom of the Church and her doctors, in order to perfect man, not merely as man, but as docile children of God.
Science: In its philosophical sense, it is the systematic organization of facts and truths around what is already known about a thing in its causes. These facts and truths, in order to be part of the science of a thing, must be proven by demonstration and thereby have acquired a certainty about them and, generally speaking, almost universal acceptance.
Sophist: One who engages logic — specifically the syllogistic form of argument — for the purpose of self-promotion. A sophist is someone who, basically, manipulates words in order to present as true what is false. He attempts this by giving the appearance of logically ordered argument, but in reality transgresses one or more rules of correct syllogistic reasoning.
Soul: The principle of life in a material being. The soul is not the cause of life, but it is the principle from which vital activity proceeds in any vegetative, sentient or rational creature. It is the substantial form of a living body.
Spirit: A living, immaterial and subsistent person who is in no way dependent on a material nature. Subsistence is that type of existence that is proper to a complete individual substance — that is, whole, self-sufficient in its nature, and incommunicable.
Stoicism: The philosophy of fatalism and determinism. All causality is pre-determined and necessary; the Stoics denied that man can act freely and voluntarily. The original teaching of Zeno, from which this philosophy derived, was that the entire universe was one living entity whose soul was God.
Subjective: Pertaining to a thing as it is known in the mind, prescinding from its objective and real existence outside the mind. In theology and ethics, pure subjectivism leads to the denial of objective truth and moral law.
Substance: That which, essentially, exists in itself. It is the subject of the being, that in which accidents inhere. The substance is that which bears the essence or nature. It is this thing here, this apple — not the redness thereof, not the roundness nor the sweetness. Substance is the thing that we are attempting to identify by describing its nature in a definition. This man is the substance man, rational animal would describe his essence.
Syllogism: A structured form of argument wherein a conclusion is drawn from the relation established between two premises. This is done by joining or separating in the conclusion the subject and predicate unequated in the premises.
Time: A measurement of change in a material thing with reference to before and after.
Transcendental: The word can signify many things: That which is beyond all predication (God); that which is common to many predicates (motion); that which is found in every predicate (plurality); being, and that which is said of all being, or follows upon being, as it is a being. In its highest sense transcendental is to be taken simply for the mode of being in its general sense, wherein the concept is universally communicable but not univocally so. (See Universal)
Transient (Action): Proceeding from one being to another by way of effective action. An act that does not remain immanent, but effects some other being.
Truism: A self-evident fact, p.e., a circle is round. A statement of the obvious, p.e., clowns are funny.
Truth: The conformity of mind with reality. Ontologically, the conformity of everything that is to the Mind of the Creator. In this sense, all that is must be true. Moral truth is the conformity of expression with the mind.
Universal: One in relation to others, etymologically. Unum versus alia. And, because one thing can be related to other things in many ways, so do universals have various modes of existence: that is, by way of signifying things (language), by way of representing things (concepts, as we use the term in epistemology), by way of universal cause (God) and by way of being — as one nature in relation to the many which share it. In its applied sense: that which is common to many. The transcendental universals are One, True, Good and Beautiful.
Virtue: A habit of the soul, not easily engaged, from which good acts become operative. Saint Augustine calls it a quality of the mind by which one lives rightly (according to reason) and which is never used for evil. As a supernatural habit, virtue is a gift of the Holy Spirit, infused into the spiritual soul and empowering the mind and the will to believe in, to hope for, and to love the true God as He wants to be believed in, longed for, and loved.
Will: One of the two spiritual faculties of the soul. It is a power that has the good for its object. The free desire to possess the good as known by the intellect. Negatively, it is the power to reject or draw away from what is known by the intellect. The proper object of the will’s repulsion is the bad.
Wisdom: The science and application of the knowledge of first principles. As a perfection of the intellect, wisdom is the economy of order among all that is knowable. It is the mind’s recognition of a hierarchy among intelligible things — in application, putting first things first. The highest wisdom is to seek to know the highest good. To attain to God is the science of the saints.