Gunk (mereology)
Encyclopedia
In mereology
, an area of philosophical logic
, the term gunk applies to any whole whose parts all have further proper parts. That is, a gunky object is not made of indivisible atoms. In contrast, an atomic individual is entirely decomposable into atoms.
If point-sized objects are always simple, then a gunky object does not have any point-sized parts. By usual accounts of gunk, such as Alfred Tarski
's in 1929, three-dimensional gunky objects also do not have other degenerate parts shaped like one-dimensional curves or two-dimensional surfaces. (See also Whitehead's point-free geometry
.)
Gunk is an important test case for accounts of the composition of material objects: for instance, Ted Sider has challenged Peter van Inwagen
's account of composition because it is inconsistent with the possibility of gunk. Sider's argument also applies to a simpler view than van Inwagen's: mereological nihilism, the view that only material simples exist. If nihilism is necessarily true, then gunk is impossible. But, as Sider argues, because gunk is both conceivable and possible, nihilism is false, or at best a contingent truth.
Gunk has also played an important role in the history of topology
(Zimmerman 1996a) and in recent debates concerning change, contact, and the structure of physical space
. The composition of space and the composition of material objects are related by receptacles - regions of space that could harbour a material object. (The term receptacles was coined by Richard Cartwright (Cartwright 1975).) It seems reasonable to assume that if space is gunky, a receptacle is gunky and then a material object is possibly gunky.
The term was first used by David Lewis
in his work Parts of Classes (1991) and "Nominalistic Set Theory" (1970). Dean W. Zimmerman defends the possibility of atomless gunk (1996b). See also Hud Hudson (2007).
Mereology
In philosophy and mathematical logic, mereology treats parts and the wholes they form...
, an area of philosophical logic
Philosophical logic
Philosophical logic is a term introduced by Bertrand Russell to represent his idea that the workings of natural language and thought can only be adequately represented by an artificial language; essentially it was his formalization program for the natural language...
, the term gunk applies to any whole whose parts all have further proper parts. That is, a gunky object is not made of indivisible atoms. In contrast, an atomic individual is entirely decomposable into atoms.
If point-sized objects are always simple, then a gunky object does not have any point-sized parts. By usual accounts of gunk, such as Alfred Tarski
Alfred Tarski
Alfred Tarski was a Polish logician and mathematician. Educated at the University of Warsaw and a member of the Lwow-Warsaw School of Logic and the Warsaw School of Mathematics and philosophy, he emigrated to the USA in 1939, and taught and carried out research in mathematics at the University of...
's in 1929, three-dimensional gunky objects also do not have other degenerate parts shaped like one-dimensional curves or two-dimensional surfaces. (See also Whitehead's point-free geometry
Whitehead's point-free geometry
In mathematics, point-free geometry is a geometry whose primitive ontological notion is region rather than point. Two axiomatic systems are set out below, one grounded in mereology, the other in mereotopology and known as connection theory...
.)
Gunk is an important test case for accounts of the composition of material objects: for instance, Ted Sider has challenged Peter van Inwagen
Peter van Inwagen
Peter van Inwagen is an American analytic philosopher and the John Cardinal O'Hara Professor of Philosophy at the University of Notre Dame. He previously taught at Syracuse University and earned his PhD from the University of Rochester under the direction of Richard Taylor and Keith Lehrer...
's account of composition because it is inconsistent with the possibility of gunk. Sider's argument also applies to a simpler view than van Inwagen's: mereological nihilism, the view that only material simples exist. If nihilism is necessarily true, then gunk is impossible. But, as Sider argues, because gunk is both conceivable and possible, nihilism is false, or at best a contingent truth.
Gunk has also played an important role in the history of topology
Topology
Topology is a major area of mathematics concerned with properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing...
(Zimmerman 1996a) and in recent debates concerning change, contact, and the structure of physical space
Space
Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...
. The composition of space and the composition of material objects are related by receptacles - regions of space that could harbour a material object. (The term receptacles was coined by Richard Cartwright (Cartwright 1975).) It seems reasonable to assume that if space is gunky, a receptacle is gunky and then a material object is possibly gunky.
The term was first used by David Lewis
David Kellogg Lewis
David Kellogg Lewis was an American philosopher. Lewis taught briefly at UCLA and then at Princeton from 1970 until his death. He is also closely associated with Australia, whose philosophical community he visited almost annually for more than thirty years...
in his work Parts of Classes (1991) and "Nominalistic Set Theory" (1970). Dean W. Zimmerman defends the possibility of atomless gunk (1996b). See also Hud Hudson (2007).