John McTaggart Ellis McTaggart (1866-1925) was a British philosopher who taught at Trinity College, Cambridge from 1897-1923. He was born John McTaggart Ellis, but his father took the surname McTaggart as a condition of an inheritance from an uncle, Sir John McTaggart, a member of the British Parliament. At Cambridge, McTaggart's friends and colleagues included Bertrand Russell and G.E. Moore. His principal writings included Studies in the Hegelian Dialectic (1896), Some Dogmas of Religion (1906), A Commentary on Hegel's Logic (1910), The Nature of Existence (1921-7), and Philosophical Essays (1934).

The Nature of Existence is a treatise that examines the relation between existence and reality. It attempts to define the extent to which the nature of existence reflects the nature of reality. It is divided into two volumes: volume I discusses the nature of existence, and volume II describes the consequences of the nature of existence for our understanding of the nature of reality.

According to McTaggart, whatever exists is real. Nothing can exist without being real, and nothing can be real without existing. Existence implies reality, and reality implies existence. There is no such thing as unreal existence, and there is no such thing as non-existent reality.

Reality is an indefinable characteristic of existing things. A characteristic may be a quality of an existing thing or a relation between existing things. There is no characteristic or possibility that does not exist. Characteristics of existing things cannot be real without existing and cannot exist without being real.

A belief may be a thought or feeling that something is real or that something exists. Beliefs may be either true or false. A belief is true if it refers or corresponds to a fact. Truth may be defined as a relation of correspondence to a fact (or to multiple facts). Falsehood may be defined as a relation of non-correspondence to a fact (or to multiple facts). Thus, every belief derives its truth or falsehood from its correspondence or non-correspondence to a fact (or to multiple facts).¹

The truth of a belief only requires the belief to correspond to a fact, and it does not require the belief to correspond to a true proposition. A belief may be true independently of whether it corresponds to a true proposition. The reality of a true belief may be different from the reality of a true proposition. A true belief may have a subjective reality, but a true proposition ay have an objective reality.

Whatever exists must have some quality besides existence. A quality may be a simple quality, a compound quality, or a complex quality. A simple quality is indefinable and unanalyzable. A compound quality may be defined and analyzed into an aggregate of other qualities. A complex quality is not an aggregate of qualities, but can be analyzed and defined by means of characteristics such as qualities or relations.

The compound quality of something can be called the nature of that thing.² If we know all the qualities of something, then we know the nature of that thing.

A substance can be defined as that which exists and which has qualities without itself being a quality or a relation.³ A substance has the quality of substantiality, but it can have this quality only if it is not itself a quality.

A simple substance is not divisible, and cannot be differentiated into a plurality of substances. A simple substance may have a plurality of aspects or qualities.

Every substance has a plurality of qualities and relations. Relations, like qualities, can be simple, compound, or complex.⁴ A simple relation cannot be analyzed into other relations. A compound relation consists of an aggregate of simple relations. A complex relation is not an aggregate of relations, but can be analyzed by means of qualities or relations.⁵

The nature of a substance may not only be described by various qualities but may consist of various qualities. The relations of a substance may be its relational qualities. Knowledge concerning the nature of a substance may consist of knowledge of the qualities of that substance.

A description of a substance, according to McTaggart, is actually a description of the qualities of that substance. A complete description of a substance is a statement of all of its qualities. An exclusive description of a substance is a description which can apply only to a particular substance and not to another. A sufficient description of a substance is a statement of qualities that are sufficient to identify that substance. A substance may have more than one sufficient description, but can have only one complete description.⁶

Substances may share the same quality. A class of substances is a category that shares one or more qualities. A group of substances, on the other hand, is a category that may not share a common quality. A class may have no members, but a group is defined by its members.

A compound substance is a substance which has substances for its parts.⁷ A simple substance cannot be divided into parts. A compound substance consists of two or more substances which do not have the same content. Substances which do not have the same content consist of different sets of parts.

Each part of a substance has a sufficient description. Thus, the nature of any substance must supply sufficient descriptions of its parts (Volume I-section 192).

For a substance to supply sufficient descriptions of all of its parts within parts to infinity, the substance must stand in a relation of determining correspondence to its parts. McTaggart asserts that the relation of determining correspondence applies to every substance throughout the universe.

An exclusive common quality is a quality which belongs to a group of substances, but does not belong to all substances. Every substance belongs to at least one group which has an exclusive common quality.⁸

Each part of the universe in some way reflects the whole universe. Thus, the universe is a self-reflecting unity.⁹

There are two modes of perception of time, says McTaggart: 1) the "A series" and 2) the "B series." The A series is a series of positions from past to present to future. The B series is a series of positions from earlier to later.

The content of any position in time defines an event. Every event includes a plurality of events, and is thus a compound substance.¹⁰ The characteristics of past, present, and future may successively belong to an event, but they cannot simultaneously belong to the same event. No event can simultaneously be a past, present, and future event. However, every event must simultaneously be related to the past, present, and future.

The reality of the A series as a mode of perception of time is contradicted by the fact that it requires incompatible characteristics of events to be simultaneously related to each other Thus, time is unreal and does not exist. Our experience of events as taking place in time is illusory.

The "C series" is a series which appears to be a time series, but is not. The C series really exists, but the A series and B series are only apparent.¹¹

Matter is anything that has size, shape, position, mobility, and impenetrability. Matter is not the same as substance, because it consists of simple parts. Matter is not infinitely divisible, because sufficent descriptions of its primary parts must include its spatial and temporal qualities, which cannot be divided into parts within parts to infinity.

Nothing that has simple parts exists, says McTaggart, and therefore matter does not exist. Simple parts cannot be subdivided into smaller parts, and therefore simple parts do not exist. There are no simple substances, and no substance consists of simple parts. Every substance is a compound substance and may be infinitely divided into a plurality of parts.

Furthermore, the self consists of spirit. The self is the part of a substance that can perceive itself and other substances. The self may be defined by its perceptions. Whatever is included in the content of the self is spiritual. The self is real, and its existence does not depend on its being perceived.¹²

The self may have perceptions of itself and of other substances. A perception may be an awareness of the qualities of a substance or of the relations of a substance to other substances. Perceptions may be direct or indirect. A direct perception may be a perception of the qualities or relations of a substance, while an indirect perception may be a perception of a perception.

Love is a principle of absolute reality, and every self will love every other self that it perceives directly (Volume II-section 470). Every self will feel affection towards every other self whom it perceives indirectly.

Because matter does not exist, all substance is spiritual. To know spirit is to know reality. Reality is not material, but spiritual.

According to McTaggart, God cannot have created the universe, because creation is a causal relation, and any causal relation requires a cause to precede an effect. Because time is unreal, we cannot show that any substance is prior in time to any other substance, and we can only demonstrate that some substances are in a causal relation to each other, which is not sufficient to establish creation.¹³

McTaggart also says that God cannot govern or control the universe, because this power would only be possible if God were the cause of events in the universe, and because the power to cause events is rendered impossible by the finding that time does not exist (Volume II-section 495).

Mystical perceptions of God are only apparent perceptions of God, says McTaggart. A mystical experience of God is actually a judgment that God exists. The judgment that God exists can be mistaken for the perception of God (Volume II-section 523).

If a substance is perceived as if it were in the realm of time, then that substance may appear as if it were in a plurality of states succeeding one another in the B series. However, such a perception is actually a misperception, since time does not exist. The C series is timeless and is the reality which is misperceived as the A series and B series. The C series is an inclusion series, although it may be miperceived as the A series or B series.

The "D series" is a series of increments in misperception of the C series. The increments of the D series are increases or decreases in the clarity and accuracy of our perceptions. The A series and the B series are modes of perception of time, but nothing actually exists in time. The C series is the reality that everything is timeless. Thus, the fundamental meaning of the C series is its direction toward more inclusion (Volume II-section 724).

Every self is timeless and spiritual. Every self may perceive itself or parts of itself. Every self may also perceive other selves and may perceive parts of other selves. Every self is a primary part of the universe (Volume II-section 434). The perceptions that selves have of themselves and of each other are secondary parts of the universe. The universe as a whole is not a self, but it includes the contents of every self. The universe is a compound substance, of which all other substances are parts (Volume I-section 135).

McTaggart rejects the existence of God, but he emphasizes the spiritual nature of reality. He presents a theory of personal idealism that describes the eternal self or spirit as the fundamental reality of the universe. The personal self is real for McTaggart, but the abolsute self is merely an abstraction. Love is a quality of the personal self that may unite the self with all other selves. Love may also bring the personal self into unity with absolute reality.

¹ John McTaggart Ellis McTaggart, The Nature of Existence, Volume I, ed. by C.D. Broad (Cambridge: Cambridge University Press, 1921), p. 23.
² Ibid., p.65.
³ Ibid., p. 68.
⁴ Ibid., p. 84.
⁵ Ibid., p. 84.
⁶ Ibid., p. 104.
⁷ Ibid., p. 138.
⁸ Ibid., p. 251.
⁹ Ibid., p. 300.
¹⁰ John McTaggart Ellis McTaggart, The Nature of Existence, Volume II, ed. by C.D. Broad (Cambridge: Cambridge University Press, 1927), p. 10.
¹¹ Ibid., p. 30.
¹² Ibid., p. 94.
¹³ Ibid., p. 179.

McTaggart, John McTaggart Ellis. The Nature of Existence. Volume I. Edited by C.D. Broad. Cambridge: Cambridge University Press, 1921.

McTaggart, John McTaggart Ellis. The Nature of Existence. Volume II. Edited by C.D. Broad. Cambridge: Cambridge University Press, 1927.