The Universal Idea

The universal idea, or simply the Universal, is an idea that represents an essence which can be common to many things and is predicable of each of those things in the same manner. Thus the idea metal represents an essence common to gold, silver, copper, lead, and so on, and the idea can be predicated of all these together and of each of them singly in the same manner: all are metals; each is equally a metal.

Most of our ideas are Universals. Even many ideas that seem singular are Universals in themselves, made singular only by the use of some qualifier like this or my. The idea father is itself a Universal; it becomes singular only in “this father,” “my father,” etc.

The word universal is derived from the Latin unum versus alia (one in relation to other things). The Universal is one — a single idea in the mind representing a single essence — but this essence may be found in a plurality of things other than the idea itself.

The inferiors of a Universal are the things or objects that have the essence which it represents. These inferiors are, first of all, ideas contained within the scope of the Universal; in a further sense, they are the extramental things represented by the Universal.

The Universal is considered in two aspects: as the Reflex Universal and as the Direct Universal.

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a) The Reflex Universal: The Five Predicables

In what modes or ways may the Universal be predicated of its inferior ideas? In five ways. These ways are called the Five Predicables (Categoremata in Aristotle). They are modes of predication — not classifications of extramental reality — in one or another of which every Universal is predicable of its inferiors.

1. Species

When a Universal is predicable of its inferior as one and coextensive with it in content, as completely defining it, the Universal is the Species of its inferior idea. Thus the Universal rational animal is the Species of its inferior idea man. In “Man is a rational animal,” the Universal completely defines the essence man. If you represent these Universals by circles, their circumferences will fall exactly one upon the other; the circles coincide.

2. Genus

When a Universal is predicable of its inferior idea as defining that part of its essence which it has in common with another Species, the Universal is the Genus of its inferior idea. Thus animal is the Genus of man. In “Man is an animal,” the Universal animal defines that part of the essence of man which man has in common with brute. A Genus always includes two Species, not completely, but according to their common part; in their non-common parts the two Species will always be contradictories, thus exhausting the possibilities.

3. Specific Difference

The common part of two Species under any Universal is their Genus. The part which is not common is their respective Specific Difference — that by which one Species is distinguished from another under a common Genus. Thus the Universal rational is the Specific Difference of its inferior man. In “Man is rational,” this Universal defines that part of the essence of man which marks it off from the other Species of the same Genus: non-rational animal (brute). Note: Genus plus Specific Difference gives the complete essence, or Species.

4. Property (Attribute)

When a Universal is predicable of its inferior idea as defining no part of its Species or essence, but as indicating something that belongs by natural necessity to that essence, the Universal is the Property or Attribute of its inferior idea. Thus risible (being that can laugh) is the Attribute of man. In “Man is risible,” the Universal risible defines no part of the essence man, but indicates something that man must have by natural necessity when his nature is fully and integrally constituted.

5. Accident

When a Universal is predicable of its inferior idea as defining no part of its Species and as belonging to it by no natural necessity — simply as happening to belong to it, or as being capable of belonging — the Universal is the Accident of its inferior idea. Thus reading being is the Accident of man. In “Man is a reading being,” this Universal defines no part of the essence man, nor indicates anything belonging to it by natural necessity; it merely indicates what may or may not be predicable of its inferior.

The cardinal principle: The Predicables are not classifications of things; they are modes of predication — modes according to which the mind applies idea to inferior idea.

The Porphyrian Tree

An important matter following from the Predicables is the Subordination of Genera and Species, graphically expressed in the Porphyrian Tree, first drawn by Porphyry (3rd century):

                    SUBSTANCE
                   /          \
           CORPOREAL          NON-CORPOREAL
               |
             BODY
            /      \
        LIVING    NON-LIVING
           |
       ORGANISM (SENTIENT)
          /               \
   RATIONAL           NON-RATIONAL
       |
  Individuals: Tom, John, Mary, Jane, etc.

Points to notice:

1. Substance is the highest genus — it is not itself a species of a higher genus. All other genera (body, organism, animal) are themselves species of higher genera.
2. Corporeal substance and non-corporeal substance are the highest species (no species in a higher order). Rational animal (man) is the lowest species — it is not in turn a genus of further species, but is predicable only of individuals.
3. Each genus considered in reference to the species immediately contained in it is called the Proximate Genus; higher genera are Remote Genera. Thus organism is the Proximate Genus of sentient and non-sentient organism, but the Remote Genus of man.
4. The branches on either side indicate Specific Difference. Each species is constituted by Proximate Genus plus Specific Difference. Thus the species living body (organism) = Proximate Genus body + Specific Difference living.
5. Each genus (except the highest) is itself a species of a higher genus. Each species (except the lowest) becomes in turn a genus of a lower species.

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b) The Direct Universal: The Ten Categories

In what classes do things, as understandable, exist in nature? In ten classes or Predicamentals (The Categories in Aristotle). These are substance and nine accidents.

Substance is a being — bodily or spiritual — that is fitted for existence in its own right, not merely as a determination or qualifier of something else. Examples: animal, man, body, soul, spirit, God, hill, tree.

Accident is a being not fitted for independent existence, but regularly requiring a substrate in which to inhere. Action, for example, is not found independently existing, but only in an acting thing.

Note the distinction: Predicamental accidents (here) are classes of understandable reality. Predicable Accident (above) is a mode of applying a Universal to its inferiors. These are entirely distinct.

The nine predicamental accidents are:

#	Accident	Description	Examples
1	Quantity	Spatial extension of bodily substance	—
2	Quality	Determination of the character of a substance	Habits (prudence, health); capacity (rationality, blindness); passive character (colour, temperature, age); bodily figure (roundness)
3	Relation	Order or standing of one thing with reference to another	likeness, identity, paternity, servitude
4	Place	Position in reference to surrounding space	in the street, at Rome, on the housetop
5	Posture	Position in reference to parts of the same body	standing, sitting, lying down
6	Time	Position with reference to past, present, or future	at two o’clock, in the evening, to-day
7	Habit	Determination of externals such as dress or equipment	armed, dressed, well caparisoned (N.B. Habit of mind or soul — studiousness, virtue — is Quality)
8	Action	The production of change; affecting an object	heating, striking, wounding
9	Passion	Receiving or suffering of change; being affected	being heated, being struck, being wounded

An ancient Latin couplet used to memorise the Predicamentals:

The tree cools the six slaves worn out by summer’s heat; To-morrow I’ll stand in the country in garments clean and neat.

Word	Predicamental
tree	Substance
cools	Action
six	Quantity
slaves	Relation (implies master)
worn out	Passion
heat	Quality
to-morrow	Time
I’ll stand	Posture
in the country	Place
in garments	Habit

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Summary of the Article

We have defined the Universal and learned what is meant by its inferiors. We have viewed the Universal in its reflex and direct aspects.

The Reflex Universal is predicable of its inferiors as their Genus, Species, Specific Difference, Property or Attribute, or Accident. These modes of predication are the Five Predicables (Categoremata).

The Direct Universal reveals that the mind grasps objective reality either as substance or as one of the nine accidents. These ten classifications of understandable reality are the Predicamentals or Categories.