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Temporal parts is a concept used in contemporary metaphysics in the debate over the persistence of material objects. Objects typically have parts that exist in space—a human body, for example, has spatial parts like hands, feet, and legs. Some metaphysicians believe objects have temporal parts as well. A temporal part would thus be something like "the first year of a person's life", or "all of a table from between 10:00 a.m. on June 21, 1994 to 11:00 p.m. on July 23, 1996".

Originally it was argued that those who believe in temporal parts believe in perdurantism, that persisting objects are wholes composed entirely of temporal parts. This view was contrasted with endurantism, the claim that objects are wholly present at any one time (thus not having different temporal parts at different times). This claim is still commonplace, but philosophers like Ted Sider believe that even endurantists should accept temporal parts.

Definition[link]

Not everyone was happy with the definition by analogy: some philosophers, such as Peter van Inwagen, argued that—even given the definition by analogy—they still had no real idea what a temporal part was meant to be (1981: 133), whilst others have felt that whether temporal parts existed or not is merely a verbal dispute (Eli Hirsch holds this view).

Gallois surveys some of the attempts to create a more specific definition (Gallois 1998: 256). The early attempts included identifying temporal parts with ordered pairs of times and objects, but it seems relatively unproblematic that temporal parts exist given the definition and ordered pairs seem unsuitable to play the role that perdurantists demand, such as being parts of persisting wholes—how can a set be a part of a material object?. Later perdurantists identified persisting objects with events, and as events having temporal parts was not problematic (for example, the first and second halves of a football match), it was imagined that persisting objects could have temporal parts. There was a reluctance from many to identify objects with events, and this definition has long since fallen out of fashion.

Of the definitions closest to those commonly used in the literature, the earliest was Thomson:

x is a cross-sectional temporal part of y =df (∃T)[y and x exist through T & no part of x exists outside T & (∀t)(t is in T ⊃ (∀P)(y exactly occupies P at t ⊃ x exactly occupies P at t))] (Thomson 1983: 207).

Later, Sider tried to combat the fears of endurantists who could not understand what a temporal part is by defining it in terms of "part at a time" or "parthood at a time", a relation that the endurantist should accept, unlike parthood simpliciter—which an endurantist may say makes no sense, given that all parts are had at a time. (However, McDaniel argues that even endurantists should accept that notion [McDaniel (2004) 146-7]). Sider gave the following definition, which is widely used:

x is an instantaneous temporal part of y at instant t =df (i) x is a part of y; (ii) x exists at, but only, at t; and (iii) x overlaps every part of y that exists at t. (Sider 2001: 60).

Sider also gave an alternative definition that is compatible with presentism, using the tensed operators "WILL" and "WAS":

x is an instantaneous temporal part of y =df (i) x is a part of y; (ii) x overlaps every part of y; (iii) it is not the case that WILL (x exists); (iv) it is not the case that WAS (x exists). (Sider 2001: 71).

While Sider's definition is most commonly used, Zimmerman—troubled by the demand for instants (which may not exist in a gunky space-time that is such that every region has a sub-region)—gives the following:

x is a temporal part of y throughout T =df (i) x exists during and only during T; (ii) for every subinterval T* of T, there is a z such that (a) z is a part of x, and (b) for all u, u has a part in common with z during T* if and only if u has a part in common with y during T*; and (iii) y exists at times outside of T. (Zimmerman 1996: 122)

The argument from temporary intrinsics[link]

Temporal parts are sometimes used to account for change. The problem of change is just that if an object x and an object y have different properties, then by Leibniz's Law, one ought to conclude that they are different. For example, if a person changes from having long hair to short hair, then the temporal-parts theorist can say that change is the difference between the temporal parts of a temporally extended object (the person). So, the person changes by having a temporal part with long hair, and a temporal part with short hair; the temporal parts are different, which is consistent with Leibniz's Law.

However, those who reject the notion that ordinary objects, like people, have temporal parts usually adopt a more common-sense view. They say that an object has properties at times. In this view, the person changes by having long hair at t, to short hair at t'. To them, there is no contradiction in thinking an object is capable of having different properties at different times.

An argument widely held to favor the concept of temporal parts arises from these points (Sider, 2001): David Lewis' argument from temporary intrinsics, which he first advanced in On The Plurality of Worlds.^{[citation needed]} The outline of the argument is as follows:

P1: There are intrinsic properties, i.e., properties had by an object independently of anything in the world.

P2: If every property had by an object is had to times, then there are no intrinsic properties.

C1: Therefore, not every property had by an object is had to times. Objects have some of their properties intrinsically, i.e., simpliciter.

P3: But only temporal parts can have their properties simpliciter.

C2: Therefore, there are temporal parts. (For this to follow, it is required that there be objects).

Premise P1 is an intuitive premise; generally we distinguish between properties and relations. An intrinsic property is just a property that something has independently of anything else; an extrinsic property is had only in relation to something. An example of an extrinsic property is "fatherhood": something is a father only if that something is a male and has a child. An example of an alleged intrinsic property is "shape".

According to Lewis (Sider, 2001), if we know what "shapes" are, we know them to be properties, not relations. However, if properties are had to times, as endurantists say, then no property is intrinsic. Even if a ball is round throughout its existence, the endurantist must say "for all times in which the ball exists, the ball is round, i.e., it is round at those times; it has the property 'being round at a time'." So, if all properties are had to times, then there are no intrinsic properties, (premise P2).

However, if we think that Lewis is right and some properties are intrinsic, then some properties are not had to times—they are had simpliciter (premise C1).

It might be said that premise P3 is more controversial. For instance, suppose a timeless world is possible. If that were so, then in that world, even if there were intrinsic properties, they would not be had by temporal parts—since by definition a timeless world has no temporal dimension, and therefore in such a world there cannot be temporal parts. However, our world is not timeless, and the possibility of timeless worlds is questionable, so it seems reasonable to think that in worlds with a temporal dimension, only temporal parts can have properties simpliciter.

This is so because temporal parts exist only at an instant, and therefore it makes no sense to speak of them as having properties at a time. Temporal parts have properties, and have a temporal location. So if person A changes from having long hair to having short hair, then that can be paraphrased by saying that there is a temporal part of A that has long hair simpliciter and another that has short hair simpliciter, and the latter is after the former in the temporal sequence; that supports premise P3.

Premise C2 follows, so long as one is not considering empty worlds—if such worlds are even possible. An empty world doesn't have objects that change by having a temporal part with a certain property and another temporal part with a certain other property.

Premise P1, the key premise of the argument, can be coherently denied even if the resulting view—the abandonment of intrinsic properties—is counterintuitive. There are, however, ways to support the argument if one accepts relationalism about space-time.

See also[link]

• Mereological Nihilism
• Mereology

References[link]

A collection of essays on persistence and temporal parts is:

v t e Time Major concepts Time Eternity Arguments for eternity Immortality History Past Present Future Futures studies Deep time Time Portal Measurement and standards Chronometry UTC UT TAI Second Minute Hour Sidereal time Solar time Time zone Metric time Decimal time Hexadecimal time Clock Astrarium History of timekeeping devices Horology Marine chronometer Sundial Water clock Calendar Day Week Month Year Tropical year Gregorian Islamic Julian Intercalation Leap second Leap year Chronology Astronomical chronology Calendar era Chronicle Dating methodologies Geochronology Geologic Time Geological history Periodization Regnal year Timeline Religion and mythology Dreamtime Kāla Kalachakra Prophecy Time and fate deities Wheel of time Philosophy A-series and B-series B-Theory of time Causality Endurantism Eternal return Eternalism Event Perdurantism Presentism Temporal finitism Temporal parts The Unreality of Time Physical sciences Time in physics Absolute time and space Arrow of time Chronon Coordinate time Planck epoch Planck time Proper time Spacetime Theory of relativity Time dilation Gravitational time dilation Time domain T-symmetry Biology Chronobiology Circadian rhythms Psychology Mental chronometry Sense of time Specious present Sociology and anthropology Long Now Foundation Time discipline Time use research Economics Time value of money Time-based currency Time Banking Related topics Carpe diem Duration Space System time Tempus fugit Time capsule Time signature Time travel

v t e Philosophy of time Concepts in time Time · Duration · A priori and a posteriori · Eternity · Event  · Action · Deterministic system · Free will · Eternal return · A-series and B-series · Temporal parts · Growing block universe Time Portal Theories of time Determinism · Temporal finitism · Fatalism · Indeterminism · Compatibilism and incompatibilism · Presentism · Eternalism · Four dimensionalism · Endurantism · Perdurantism  · B-Theory of time Related articles Metaphysics · Etiology · Teleology · Post hoc ergo propter hoc · The Unreality of Time

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Jonas Hellborg
Background information
Birth name	Jonas Hellborg
Born	(1958-06-07) June 7, 1958 (age 54)
Origin	Sweden
Genres	Jazz, jazz fusion, jazz metal
Occupations	Musician, composer
Instruments	Bass
Associated acts	John McLaughlin, Bill Laswell, Shawn Lane
Notable instruments
Warwick signature bass Aria signature bass

Jonas Hellborg (born June 7, 1958) is a Swedish bass guitarist. He has collaborated with John McLaughlin, Ustad Sultan Khan, Fazal Qureshi, Bill Laswell, Shawn Lane, Jens Johansson, Michael Shrieve, V. Selvaganesh, Mattias IA Eklundh and Buckethead.

Recording career[link]

Hellborg began his music career in 1976 in Sweden touring with local rock acts. He was spotted by percussionist Reebop Kwaku Baah in a small club in Stockholm 1979 and he moved to London for a year to work with Reebop on different projects. He played the Montreux Jazz festival in Switzerland in 1981 and met Michael Brecker who introduced him to John McLaughlin, Billy Cobham and other fusion stars. He was asked to join John McLaughlin’s reformed Mahavishnu Orchestra in 1983 and he stayed with McLaughlin until 1988 touring and recording with Mahavishnu Orchestra and also doing several duet tours with McLaughlin during this time.

In 1986 and 1987 he toured with a project featuring Ginger Baker on drums and Bernie Worrell on keyboards.

In 1988 Hellborg moved to New York and started his own band which first included keyboardist Aydin Esen and drummer Kenwood Dennard, later the Johansson Brothers, Jens on keyboards and Anders on drums. At the same time he started a recording studio together with producer/bassist Bill Laswell called Greenpoint Studios. They recorded a multitude of records there until early 1993, including The Word together with Tony Williams, Octave of the Holy Innocents with Mike Shrieve and Buckethead, Materials Hallucination Engine, E with the Johansson Brothers.

In 1993 he sold his part in the studio to Laswell and resettled in Paris, France. The following year he teamed up with guitarist Shawn Lane, a cooperation that would last 9 years. The first record was Abstract Logic with Ginger Baker's son Kofi on drums; this was followed by Michael Shrieve’s “Two Doors”. By the third record they were joined by drummer Jeff Sipe and embarked on long stretch that produced 4 records and a lot of touring between 1995 and 1997.

In 1998 Hellborg met percussionist V. Selvaganesh at a Zakir Hussain concert in Paris. The two formed another long lasting musical partnership that has been ongoing since then. To start with Selvaganesh joined Hellborg in duets and in different “classical” settings Hellborg was working on at the time. Later a group was formed first in trio with Lane then grew into a quintet including Selvaganesh’s 2 brothers V. Umashankar and V. Umamahesh. 2 CD’s and a DVD were produced with this group. After Shawn Lane's death in 2003, Hellborg has continued to explore amalgamations of Indian and Western music, working with Indian masters as Debashish Bhattacharya, Niladri Kumar, Vikku Vinayakram, Tanmoy Bose and U. Shrinivas. He has also started a new Metal-Fusion project with guitarist Mattias IA Eklundh called Art Metal.

Hellborg founded his own record label Day Eight Music in 1979 releasing his first solo bass record The Bassic Thing – an early showcase of his pioneering chordal, and for the time very advanced, slapping approaches. It is also noteworthy that it was the first LP ever to feature solely bass guitar. With the move to the US a new entity was formed called Bardo Music that took over the responsibilities of Hellborgs output now counting around 40 odd releases.

Musical equipment[link]

Hellborg has been involved in instrument design from early on in his career. His work includes a signature model for Aria, the first ever biamped bass amplifier (in cooperation with Italian company FBT), a double neck bass, fretted and fretless, for British company Wal in 1983 and, in 1984, an acoustic bass in collaboration with master luthier Abraham Wechter.

After working with a further half dozen of other companies with signature models and inventions he now, together with Warwick, created a new bass and a high end line of bass amplification.

Hellborg has published 2 books in the early 80’s with Music Sales of London, one on slap bass called Thumb Bassics, and a chord book called Chord Bassics.

Discography[link]

As band leader

• The Bassic Thing (solo bass)(1979), Day Eight Music
• Elegant Punk (solo bass)(1984), Day Eight Music
• Axis (1988), Day Eight Music
• Adfa (1989), Day Eight Music
• Bass, Day Eight Music
• The Silent Life (acoustic solo bass) (1991), Day Eight Music
• Jonas Hellborg Group (1990), Day Eight Music
• Jonas Hellborg Group E (1991), Day Eight Music
• The Word (1991), Axiom
• Ars Moriende (1994), Day Eight Music (with Glen Velez)
• Abstract Logic, Bardo
• Octave of the Holy Innocents (1993), Day Eight Music (re-released 2003, Bardo)
• Temporal Analogues of Paradise, Bardo
• Time Is the Enemy, Bardo
• Aram of the 2 Rivers (1999), Bardo
• Zenhouse (1999), Bardo
• Good People in Times of Evil, Bardo
• Personae, Bardo
• Icon: A Transcontinental Gathering, Bardo
• Paris (DVD) Bardo
• Kali's Son (2006), Bardo
• Art Metal (2007), Bardo

With The Mahavishnu Orchestra

• Mahavishnu, (1984) Warner Bros.
• Adventures in Radioland, (1986) Relativity

With Deadline

• Dissident (1991), Day Eight Music
• Down by Law, Cell

With Michael Joseph Smith

• Faces, Day Eight Music
• All our steps, Day Eight Music

With Michael Shrieve

• Two Doors, CMP
• THE LEAVING TIME,NOVUS/BMG

With Public Image Ltd

• Album, Virgin

With Trilok Gurtu

• Usfret, CMP

With Sultan Khan and Fazal Qureshi

• Friends Across Boundaries, Ninaad Music

With Ginger Baker

• Unseen Rain, Day Eight Music
• Middle Passage, Axiom

With Kollektiv

• feat. Jonas Hellborg, ITM

With Jens Johansson

• Fjäderlösa tvåfotingar, Day Eight Music

With Anders Johansson

• Shutka, Day Eight Music
• Red Shift, Heptagon

With RAF (feat. Peter Brötzmann, Bill Laswell, Jamal Evans)

• Ode to a Tractor (1992), Day Eight Music

With Reebop

• Melodies in a Jungle Man's Head, Day Eight Music

With Shining Path

• No Other World (1992)

With Busch-Werk

• Busch-Werk & the Masters of Groove (DVD) (2009), Zauberhaus-Records (feat. Nippy Noya,Famoudou Konaté and others)
• Trance (2011), Zauberhaus-Records (feat. Nippy Noya,Famoudou Konaté, Baba Sissoko and others)

External links[link]

• Hellborg's personal site
• Hellborg's group site
• Jonas Helborg fansite
• Bardo Records (Jonas' label) website
• Warwick's Hellborg site
• Warwick's regular site