McTaggart's Unreality of Time: The Contradictory A-Series

One response to McTaggart's paradox, the tenseless or B theory response, accepts McTaggart's argument that the A series is contradictory but denies that time requires the A series. It argues that the B series is sufficient for real time—that earlier-later relations constitute time, and passage is an illusion, a feature of our temporal perspective. The universe exists as a four-dimensional block, a block universe where all times are equally real and past, present, and future are not objective features of reality but are indexical, relative to a perspective. This B theory has become orthodoxy in philosophy of time, widely accepted as avoiding McTaggart's paradox while preserving the reality of time. Another response, the tensed or A theory response, denies that the A series is contradictory, arguing that McTaggart's argument involves a mistake—that A series properties are not really contradictory because they are indexed to times in a non-propositional way. The meeting being future at t1 and past at t2 is not contradictory—it is just the normal way temporal properties work. A-theorists argue that passage is real, that the present is objectively real, that the future is open and the past is fixed, and that McTaggart's argument fails because it assumes A series properties must be simultaneous to be contradictory when they are not.

Arthur Prior invented tense logic with two diamonds: F (forward-looking, future) and P (backward-looking, past). Corresponding boxes are G (always in the future) and H (always in the past). For example, Fφ means 'at some point in the future φ', while Gφ means 'at all points in the future φ'. Prior realized that the validity of formulas like Fφ → FFφ implied that time was dense (between any two points there was a third), and he recognized that his language couldn't express irreflexivity (no temporal point precedes itself).

John McTaggart, an early 20th-century philosopher, developed two theories of time. The A-series (tensed theory) centers on the present moment, distinguishing past, present, and future. The B-series (untensed theory) uses time coordinates (like labeling moments from the Big Bang) without reference to past/present/future. McTaggart argued both theories are internally incoherent, concluding that time itself is unreal—a position known as McTaggartian anti-realism.

On a tenseless theory, God is the creator of the universe in the sense that the whole spacetime block and everything in it depends upon God for its existence. By a single timeless act, God makes it exist and causes all events to happen at their tenseless temporal locations. God never acquires or loses relations—He timelessly stands in the creator relation to all events at their respective times. There are no tensed facts; linguistic tense is merely egocentric, expressing subjective perspective. There is no objective truth about what is now happening—'now' merely signifies the time relative to which the judgment is made. Arguments for tensed theory: tensed sentences correspond to tensed facts and cannot be translated into tenseless sentences; experience of temporal becoming is veridical. Arguments against tensed theory: McTaggart's paradox results from marrying tenseless ontology with objective temporal becoming; passage of time is a metaphor. Arguments for tenseless theory: temporal becoming is compatible with relativity theory under neo-Lorentzian interpretation; physics time is an abstraction omitting indexical elements. Arguments against tenseless theory: relations ordering events are only gratuitously regarded as temporal; mind-dependent becoming is self-defeating.

The A theory, also called the dynamic or tensed theory of time, holds that time consists of moments ordered by past, present, and future which are real and objective aspects of reality. In this view, the past no longer exists, the present is real, and the future is pure potentiality that has not yet come to be. Things in time come into existence and pass out of existence, creating real objective temporal becoming. This theory uses tenses (past tense, present tense, future tense) to express objective features of reality.

J.M.E. McTaggart, a British idealist philosopher, proposed that time consists of three series: the A-Series (past, present, future) which he argued contains logical contradictions because events move from future to present to past; the B-Series (before, during, after) which is logically consistent but static; and the C-Series, a non-temporal reality that explains both the A-Series and B-Series as mere appearances. McTaggart concluded that time is illusory, with only the C-Series being real, though he maintained that individuals themselves are fundamental categories of reality, distinguishing his 'personal idealism' from absolute idealism.

McTaggart introduces the C-series as a non-temporal series of permanent relations between events—order without temporal passage. He argues that time requires both an A-series (for change) and a C-series (for permanent order), with the B-series emerging from their combination. McTaggart contends that while both distinctions are essential to time, the A-series is more fundamental because it cannot be defined—it can only be shown by examples. He responds to objections: fictional series aren't really in time, but when believed to be existent, they're believed to be in an A-series; multiple independent time series don't contradict his thesis since the theory lacks positive evidence. The essentiality of the A-series for time remains valid.

J.M.E. McTaggart developed a sophisticated analysis of time distinguishing three series: the A series (past-present-future) which changes as time progresses, the B series (earlier-later relationships) which are eternally true and tenseless, and the C series which represents a non-temporal order underlying both. McTaggart argued that the A series is illusory because facts don't change only in respect to it. This analysis implies that principles applicable to any time—whether past or future—are uniformly applicable across all times. Understanding time as a whole requires a uniform methodology that transcends naive presentism, representing a fundamental shift in how we conceptualize temporal experience.

McTaggart introduces three distinct ways to conceptualize time. The C series describes events through objective betweenness - some events are between others (e.g., Leonard Cohen recording is between McTaggart's paper and the video). This lacks directionality and represents what McTaggart considers genuinely real. The B series adds temporal distance and direction using statements like 'A happened 170 years before B,' which are timeless truths that never change. The A series describes events in terms of their temporal status relative to the present - future, present, or past. McTaggart argues that for time to exist, an A series must be present, but since the A series is logically inconsistent, time cannot be real.

McTaggart's positive account involves a B series, an A series with pastness, presentness, and futurity, and temporal becoming. There is another interpretation where temporal relations are analyzable in terms of the application of the A series to the non-temporal C series. The direction of time is grounded in A properties moving along a non-temporal C series. On the modified A theory, temporal relations are not primitive but depend on A characteristics, and events cannot stand in temporal relations unless they exemplify A properties.

This concluding section presents McTaggart's influential argument that time as we experience it—with present, past, and future determinations—is ultimately unreal. When imagining a world without observers, these temporal determinations lose their meaning. Only temporal relations between events (before, after, simultaneously) seem to have objective reality independent of consciousness. This divides philosophical doctrines: philosophy of concept (Aristotle, Carnap) reduces time to orders of succession and relations, treating temporal determinations as subjective; philosophy of consciousness (Saint Augustine, Bergson) holds that time cannot be conceived without present, past, and future determinations which are irreducible. Einstein himself was troubled by the problem of the present moment, noting that while physics can describe temporal succession, it cannot explain why the present has special significance for human experience—a difference that cannot be demonstrated within physics.

In 1908, John McTaggart published a revolutionary article arguing that time does not exist. He divided time into two series: B-Series (static sequence of events organized as 'earlier than' and 'later than') and A-Series (dynamic experience with past, present, and future). McTaggart argued that while B-Series alone creates a frozen sequence, real time requires A-Series with flowing present. However, he proved this creates contradiction: any event was once future, became present, and is now past—three mutually exclusive properties simultaneously. This infinite regress destroys the concept of real time. The most influential response is the Block Universe theory, which proposes that all of spacetime—past, present, and future—exists simultaneously as a single block. We don't move through time; instead, we are extended objects within this four-dimensional structure. What we call 'now' is merely a slice we experience, while all other slices exist equally. Change is just difference between points in the block, not actual temporal becoming. This theory surprisingly aligns well with Einstein's relativity, suggesting McTaggart may have been partially correct about time's nature.

In Einstein's theory of relativity, there is no universal now. Two observers moving differently through space may disagree about whether two events happened at the same time, and they would both be right. The past, present, and future aren't universal but are smeared across your frame of reference. Philosopher John McTaggart divided time into two models: the A-series (past, present, future) and the B-series (before and after). He argued that the A-series is logically incoherent because it requires time to move relative to something else, leading to an infinite regress. Time may not be fundamental but an illusion emerging from the dance of hidden variables, deeper dimensions, and more primitive rules.

The Einsteinian revolution transformed physics of time completely. Special relativity eliminated Newton's absolute time by demonstrating that simultaneity is relative to the observer's reference frame and that the rate of passage of time depends on relative velocity. General relativity added dependence of the rate of passage of time on the gravitational field. If simultaneity is relative, then the set of events that compose the present of any observer is different from the present of any other observer in relative motion. There is no universal present shared by all observers. Philosophers like Hilary Putnam have argued that this relativity of the present implies that all moments of time, past, present, and future, have the same ontological reality—a view called eternalism or the block universe.

The alternative view of time holds that time does not flow, and that the categories of past, present, and future describe how we experience reality rather than how reality actually is. According to this view, there are no events that belong to the past, present, or future in reality; these are categories we apply to events for various reasons. This view has gained significant support from McTaggart's logical argument (1908, 1925) that the naive view leads to logical contradiction, and from interpretations of Einstein's relativity theory. Einstein's special relativity has been interpreted to support the static view, where past, present, and future are not objective categories but subjective categories describing how humans experience reality. The events in the universe are arranged in a four-dimensional block universe, where all events exist simultaneously, and the distinction between past, present, and future is a matter of perspective rather than objective reality.