Mereological essentialism
Encyclopedia
Mereological essentialism is a philosophical thesis about the relationship between wholes and its parts, and the conditions for their persistence. It holds the view that objects have their parts essentially, implying that if an object were to lose or gain a part, it would cease to exist—that is, it would no longer be the original object but a new, different one.
, or thought, if mereological essentialism is true, has its parts essentially; the concepts that make up the proposition are essential to it.
Further, in the case of material concrete objects, mereological essentialism can be true in different senses depending on how such objects are thought to persist through time, these senses going under the names endurantism
and perdurantism
. Mereological essentialism for enduring objects - objects that persist by being wholly present every instant, means that the enduring objects only have their spatial parts essentially. Mereological essentialism for perduring objects - objects that are spread out with parts both in space and time, have also their temporal parts
essentially in addition to their spatial parts.
Finally, what does it mean for an object to have something essentially? The usual way to explain essentiality is by reference to necessity or possible worlds. Mereological essentialism is then the thesis that objects have their parts necessarily or objects have their parts in every possible world in which the object exists.
and Gottfried Leibniz
. In the 20th century, we have G.E. Moore, Roderick Chisholm
and James Van Cleve. The last two philosophers consider objects as enduring. Michael Jubien and Mark Heller, writing from the end of the 20th and the beginning of the 21st century, defend mereological essentialism for perduring objects.
. Because it is hard to find a middle place at which to stop, the best way could be to defend mereological essentialism (Chisholm 1973).
One way to solve this puzzle is to deny that Deon has any proper parts. Defending this view is rejecting the principle of arbitrary undetached parts (Van Inwagen 1981). It means that a cup in front of you doesn't have a left part, a right part, a part where the ear of the cup is or a part where the coffee is stored (if the hole of the cup is a part of the cup).
. Masses of matter come in different quantities. We have for instance a gram of gold. There is a grammatical difference between stuff and things. We cannot say, take a gold, but must say a lump of gold (Simons 1987). Our standard way of quantifying is at most a way for the mind to project thinghood onto the world. If the world is made only of stuff, mereological essentialism must be true.
The argument from a world made only of stuff was first noted by van Cleve (1986). Defenders of a stuff ontology are Michael Jubien (1993) and Mark Heller (1990).
s clear arguments against mereological essentialism have not yet been raised. The most common counterargument is that mereological essentialism entails that an object which undergoes a subtle change is not the same object. This seems to be directly contrary to common sense. For example, if my car gets a flat tire and I then replace the tire, mereological essentialism entails that it is not the same car. This goes against a commonly held supposition.
or organ transplantation. Or as humans we might have our hair or fingernails cut. All of these procedures do not seem to lead to the nonexistence of the person or for that matter the nonexistence of the living organism. Therefore mereological essentialism cannot be universally true (Plantinga 1975).
Also, if the mereological essentialist believes in presentism
, then this argument may fail to convince them. A person who believes in presentism believes that the present is the only relevantly true world. This view is a response to the problem of Qualitative Change.
Definition
The above statement of mereological essentialism requires some elaboration. First, what types of objects: abstract or concrete objects? Mereological essentialism is most commonly taken to be a thesis about concrete material objects, but it can also be considered true of a set or proposition. A propositionProposition
In logic and philosophy, the term proposition refers to either the "content" or "meaning" of a meaningful declarative sentence or the pattern of symbols, marks, or sounds that make up a meaningful declarative sentence...
, or thought, if mereological essentialism is true, has its parts essentially; the concepts that make up the proposition are essential to it.
Further, in the case of material concrete objects, mereological essentialism can be true in different senses depending on how such objects are thought to persist through time, these senses going under the names endurantism
Endurantism
Endurantism or endurance theory is a philosophical theory of persistence and identity. According to the endurantist view material objects are persisting three-dimensional individuals wholly present at every moment of their existence...
and perdurantism
Perdurantism
Perdurantism or perdurance theory is a philosophical theory of persistence and identity. The perdurantist view is that an individual has distinct temporal parts throughout its existence....
. Mereological essentialism for enduring objects - objects that persist by being wholly present every instant, means that the enduring objects only have their spatial parts essentially. Mereological essentialism for perduring objects - objects that are spread out with parts both in space and time, have also their temporal parts
Temporal parts
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...
essentially in addition to their spatial parts.
Finally, what does it mean for an object to have something essentially? The usual way to explain essentiality is by reference to necessity or possible worlds. Mereological essentialism is then the thesis that objects have their parts necessarily or objects have their parts in every possible world in which the object exists.
Contenders
Mereological essentialism is a position defended in the debate regarding material constitution. What is the relationship between, for instance, a statue and the lump of clay from which it is made. Several different answers are proposed. Take coincidentialism, the view that there are two objects located at the same place. The lump of clay should be distinguished from the statue because they have different persistence conditions. The lump would not survive the loss of a very small part of clay, but the statue would. The statue would not survive being squashed into a ball, but the lump of clay would.Defenders
The following philosophers have thought mereological essentialism to be true; before the 20th century, Peter AbelardPeter Abelard
Peter Abelard was a medieval French scholastic philosopher, theologian and preeminent logician. The story of his affair with and love for Héloïse has become legendary...
and Gottfried Leibniz
Gottfried Leibniz
Gottfried Wilhelm Leibniz was a German philosopher and mathematician. He wrote in different languages, primarily in Latin , French and German ....
. In the 20th century, we have G.E. Moore, Roderick Chisholm
Roderick Chisholm
Roderick M. Chisholm was an American philosopher known for his work on epistemology, metaphysics, free will, and the philosophy of perception. He received his Ph.D. at Harvard University under Clarence Irving Lewis and Donald C. Williams, and taught at Brown University...
and James Van Cleve. The last two philosophers consider objects as enduring. Michael Jubien and Mark Heller, writing from the end of the 20th and the beginning of the 21st century, defend mereological essentialism for perduring objects.
Arguments for
There are several arguments for mereological essentialism. Some are more formal and others take mereological essentialism as solutions to philosophical puzzles or paradoxes. (This approach is, for instance, mentioned in Olson (2006).)The argument from bad alternatives
What would be the opposite of mereological essentialism? It would be that objects would survive the loss of any part, call it mereological inessentialism. But mereological inessentialism means that a table would survive replacement or loss of any of its parts. By successive replacement we could change the parts of the table so in the end it would look like a chair. This is a version of a Sorites paradoxSorites paradox
The sorites paradox is a paradox that arises from vague predicates. The paradox of the heap is an example of this paradox which arises when one considers a heap of sand, from which grains are individually removed...
. Because it is hard to find a middle place at which to stop, the best way could be to defend mereological essentialism (Chisholm 1973).
"Deon and Theon" argument
Imagine a person called Deon. He has a proper part, his foot. One day he loses his foot. The resulting entity is then known as Theon. But it seems that Theon existed when Deon existed, being a proper part of Deon—namely the complement of Deon's foot, Deon minus his foot. Did Deon survive? If he did, Deon and Theon are identical and Theon is a proper part of Deon. This, however, is impossible.One way to solve this puzzle is to deny that Deon has any proper parts. Defending this view is rejecting the principle of arbitrary undetached parts (Van Inwagen 1981). It means that a cup in front of you doesn't have a left part, a right part, a part where the ear of the cup is or a part where the coffee is stored (if the hole of the cup is a part of the cup).
A world made only of stuff
Some philosophers reject the existence of individual objects. The world does not contain single, individuable objects which we can use logic to quantify. Instead the world only contains stuff or masses of matterMatter (philosophy)
Matter is the substrate from which physical existence is derived, remaining more or less constant amid changes. anything that occupies space and has mass and weight...
. Masses of matter come in different quantities. We have for instance a gram of gold. There is a grammatical difference between stuff and things. We cannot say, take a gold, but must say a lump of gold (Simons 1987). Our standard way of quantifying is at most a way for the mind to project thinghood onto the world. If the world is made only of stuff, mereological essentialism must be true.
The argument from a world made only of stuff was first noted by van Cleve (1986). Defenders of a stuff ontology are Michael Jubien (1993) and Mark Heller (1990).
Arguments against
Because mereology is a new branch of formal systemFormal system
In formal logic, a formal system consists of a formal language and a set of inference rules, used to derive an expression from one or more other premises that are antecedently supposed or derived . The axioms and rules may be called a deductive apparatus...
s clear arguments against mereological essentialism have not yet been raised. The most common counterargument is that mereological essentialism entails that an object which undergoes a subtle change is not the same object. This seems to be directly contrary to common sense. For example, if my car gets a flat tire and I then replace the tire, mereological essentialism entails that it is not the same car. This goes against a commonly held supposition.
The argument from a paradigmatic example
The most common argument against mereological essentialism is the view that it cannot be universally true. Take us, ourself, persons. We are humans, living organisms. As organisms we survive by having our parts replaced by, for instance, metabolismMetabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
or organ transplantation. Or as humans we might have our hair or fingernails cut. All of these procedures do not seem to lead to the nonexistence of the person or for that matter the nonexistence of the living organism. Therefore mereological essentialism cannot be universally true (Plantinga 1975).
Also, if the mereological essentialist believes in presentism
Presentism (philosophy of time)
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...
, then this argument may fail to convince them. A person who believes in presentism believes that the present is the only relevantly true world. This view is a response to the problem of Qualitative Change.
See also
- HumanHumanHumans are the only living species in the Homo genus...
- Mereological NihilismMereological nihilismMereological nihilism is the position that objects with proper parts do not exist , and only basic building blocks without parts exist...
- MereologyMereologyIn philosophy and mathematical logic, mereology treats parts and the wholes they form...
- PersonPersonA person is a human being, or an entity that has certain capacities or attributes strongly associated with being human , for example in a particular moral or legal context...
- Peter van InwagenPeter van InwagenPeter 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...
- Temporal PartsTemporal partsTemporal 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...
- Ship of TheseusShip of TheseusThe Ship of Theseus, also known as Theseus' paradox, or various variants, notably grandfather's axe and Trigger's Broom is a paradox that raises the question of whether an object which has had all its component parts replaced remains fundamentally the same object.The paradox is most notably...