Presentism (philosophy of time)

In the philosophy of time, presentism is the belief that only the present exists and the future and the past are unreal. Past and future "entities" are to be construed as logical constructions or fictions. The opposite of presentism is 'eternalism', which is the belief that things in the past and things yet to come exist eternally. One other view (that has not been held by very many philosophers) is sometimes called the 'growing block' theory of time, which is a theory that takes the past and present to exist but the future to be nonexistent. [cite book| last=Broad| first= C.D.| title= Scientific Thought| location=New York| publisher=Harcourt, Brace and Co.| year=1923| url=http://www.ditext.com/broad/st/st-con.html] Presentism is compatible with Galilean relativity, in which time is independent of space but is probably incompatible with Lorentzian/Einsteinian relativity in conjunction with certain other philosophical theses which many find uncontroversial. Presentism can also be used more loosely to refer to a narrow focus on the conditions of the moment.Or|date=January 2008

Saint Augustine proposed that the present is a knife edge between the past and the future and could not contain any extended period of time. This seems evident because, if the present is extended, it must have separate parts - but these must be simultaneous if they are truly part of the present. According to early philosophers time cannot be both past and simultaneously present, so it is not extended. Contrary to Saint Augustine, some philosophers propose that conscious experience is extended in time. For instance, William James said that time is "the short duration of which we are immediately and incessantly sensible".Fact|date=February 2008 Augustine proposed that God is outside of time and present for all times, in eternity. Other early philosophers who were presentists include the Buddhists (in the tradition of Indian Buddhism). A leading scholar from the modern era on Buddhist philosophy is Stcherbatsky, who has written extensively on Buddhist presentism: "Everything past is unreal, everything future is unreal, everything imagined, absent, mental... is unreal... Ultimately real is only the present moment of physical efficiency [i.e., causation] ." [Vol.1 of "Buddhist Logic", 1962, Dover: New York. 70-71.]

According to J. M. E. McTaggart's "The Unreality of Time" there are two ways of referring to events: the 'A Series' (also known as 'tensed time': yesterday, today, tomorrow) and the 'B Series' (or 'untensed time': Monday, Tuesday, Wednesday). Presentism is the belief that the 'A Series' is fundamental and that B Series facts can be explained or reduced to A series facts. Presentists maintain that temporal discourse requires the use of tenses. All presentists are A theorists, but not all A theorists are presentists; some A theorists deny that future entities exist, but accept past existents into their ontology; other A theorists accept the existence of past and future individuals.Fact|date=February 2008

In the modern theory of relativity, the conceptual observer is at a geometric point in both space and time at the apex of the 'light cone' which observes events laid out in time as well as space. Different observers can disagree on whether two events at different locations occurred simultaneously depending if the observers are in relative motion (see relativity of simultaneity). This theory depends upon the idea of time as an extended thing and has been confirmed by experiment and has given rise to a philosophical viewpoint known as four dimensionalism. However, although the contents of an observation are time-extended, the conceptual observer, being a geometric point at the origin of the light cone, is not extended in time or space. This analysis contains a paradox in which the conceptual observer contains nothing, even though any real observer would need to be the extended contents of an observation to exist. This paradox is partially resolved in Relativity theory by defining a 'frame of reference' to encompass the measuring instruments used by an observer. This reduces the time separation between instruments to a set of constant intervals. [ [http://philsci-archive.pitt.edu/archive/00002408/ Petkov 2005] ]

ee also

* Consciousness
* Growing block universe
* Metaphysics

References

External links

* [http://philsci-archive.pitt.edu/archive/00000525/00/presentism_and_relativity.pdf Balashov, Y., Janssen, M. (2002). Presentism and Relativity. Preprint of article in British Journal for the Philosophy of Science.]
* [http://www.oup.com/uk/catalogue/?ci=9780199212804 Bourne, Craig (2006). A Future for presentism. Oxford: Oxford University Press.] First book that defends Presentism.
* [http://www.abstractatom.com/buddhist_philosophy_of_time_article_jeffrey_grupp.htm Buddhist Philosophy of Presentism]
* [http://www.nd.edu/~mrea/Online%20Papers/Four%20Dimensionalism.pdf Four Dimensionalism. M.C.Rea. The Oxford Handbook for Metaphysics.] Describes Presentism and how four dimensionalism contradicts it.
* [http://www.geocities.com/trolleylauncher/AJPPresentismConsciousnessFinalVersion.htm McKinnon, N. (2003) Presentism and Consciousness. Australasian Journal of Philosophy. 81, 4. p305.]
* [http://philsci-archive.pitt.edu/archive/00002408/ Vesselin Petkov. (2005) Is There an Alternative to the Block Universe View?]