The Unreality of Time
"The Unreality of Time" is the best-known philosophical work of University of Cambridge idealist J. M. E. McTaggart (1866–1925). In the argument, first published as a journal article in Mind in 1908, McTaggart argues that time is unreal because our descriptions of time are either contradictory, circular, or insufficient. A slightly different version of the argument appeared in 1927 as one of the chapters in the second volume of McTaggart's greatest work, The Nature of Existence.[1]
The argument for the unreality of time is popularly treated as a stand-alone argument that does not depend on any significant metaphysical principles (e.g. as argued by C. D. Broad 1933 and L. O. Mink 1960). R. D. Ingthorsson disputes this, and argues that the argument can only be understood as an attempt to draw out certain consequences of the metaphysical system that McTaggart presents in the first volume of The Nature of Existence (Ingthorsson 1998 & 2016).
It is helpful to consider the argument as consisting of three parts. In the first part, McTaggart offers a phenomenological analysis of the appearance of time, in terms of the now famous A- and B-series (see below for detail). In the second part, he argues that a conception of time as only forming a B-series but not an A-series is an inadequate conception of time because the B-series does not contain any notion of change. The A-series, on the other hand, appears to contain change and is thus more likely to be an adequate conception of time. In the third and final part, he argues that the conception of time forming an A-series is contradictory and thus nothing can be like an A-series. Since the A- and the B- series exhaust possible conceptions of how reality can be temporal, and neither is adequate, the conclusion McTaggart reaches is that reality is not temporal at all.
The atemporality of the B-series[edit]
McTaggart argues that the conception of time as only forming a B-series is inadequate because the B-series does not change, and change is of the essence of time. If any conception of reality represents it as changeless, then this is a conception of an atemporal reality. The B-series does not change because earlier-later relationships never change (e.g. the year 2010 is always later than 2000). The events that form a B-series must therefore also form an A-series in order to count as being in time, i.e. they must pass from future to present, and from present to past, in order to change.
The A- and B-series are not mutually exclusive. If events form an A-series they automatically also form a B-series (anything in the present is earlier than anything in the future, and later than everything past). The question is not therefore whether time forms an A- or a B-series; the question is whether time forms both an A- and a B-series, or only a B-series.
The proponents of the B-view of time typically respond by arguing that even if events do not change their positions in the B-series, it does not follow that there can be no change in the B-series. This conclusion only follows if it is assumed that events are the only entities that can change. There can be change in the B-series in the form of objects bearing different properties at different times (Braithwaite 1928; Gotshalk 1930; Marhenke 1935; Smart 1949; Mellor 1981 & 98; Oaklander 1984; LePoidevin 1991; Dyke 2002).[3]
The suggestion that the B-view of time can escape the problem by appealing to particulars that endure through time and have different properties at different times is controversial in its own right, but it is generally assumed that this is a controversy that has nothing to do with McTaggart. Instead it is treated as a separate issue, the question of whether things can endure in B-time. However, as Ingthorsson has argued, McTaggart does discuss variation in the properties of persistent entities in the 1st Volume of The Nature of Existence, and there comes to the conclusion that variation in the properties of things between times is not change but mere variation between the temporal parts of things (Ingthorsson 2001).
The C-series[edit]
Having come to the conclusion that reality can neither form an A- nor a B-series, despite appearances to the contrary, then McTaggart finds it necessary to explain what the world is really like such that it appears to be different from what it appears to be. Here is where the C-series comes into play. McTaggart does not say much about the C-series in the original journal article, but in The Nature of Existence he devotes six whole chapters to discuss it (1927: Chs. 44–9).
The C-series is rarely given much attention. When it is mentioned, it is described as "an expression synonymous with 'B-series' when the latter is shorn of its temporal connotations" (Shorter 1986: 226). There is a grain of truth in this, but there is more to the C-series than this. Stripping the temporal features from the B-series only gives what the C- and B-series have minimally in common, notably the constituents of the series and the formal characteristics of being linear, asymmetric, and transitive. However, the C-series has features that the B-series does not have. The constituents of the C-series are mental states (a consequence of McTaggart's argument in Ch. 34 of The Nature of Existence that reality cannot really be material), which are related to each other on the basis of their conceptual content in terms of being included in and inclusive of (1927: sect. 566 & Ch. 60). These atemporal relations are meant to provide what the earlier/later than relation cannot, notably explain why an illusion of change and temporal succession can arise in an atemporal reality.
Influence[edit]
McTaggart's argument has had an enormous influence on the philosophy of time. His phenomenological analysis of the appearance of time has been accepted as good and true even by those who firmly deny the end conclusion that time is unreal. For instance, J. S. Findlay (1940) and A. Prior (1967) took McTaggart's phenomenological analysis as their point of departure in the development of modern tense logic.
McTaggart's characterisation of the appearance of time in terms of the A- and B-series served to sharpen the contrast between the two emerging and rival views of time that we now know as the A- and B-views of time. The assumption is that the A-view, in accepting the reality of tense, represent time as being like an A-series, and that the B-view, in rejecting the reality of tense, represent time as being like a B-series.
The two objections that McTaggart develops against the conception of time as forming an A- and a B-series are still the two main objections with which the A- and B-views of time struggle. Notably, is the A-view contradictory, and is the B-view able to incorporate an account of change?
The controversy about McTaggart's argument for the unreality of time continues unabated (see, for instance, Smith 2011; Cameron 2015; Mozersky 2015; Ingthorsson 2016).
