What is Ontology: Definition and 33 Discussions

Ontology is the branch of philosophy that studies concepts such as existence, being, becoming, and reality. It includes the questions of how entities are grouped into basic categories and which of these entities exist on the most fundamental level. Ontology is sometimes referred to as the science of being and belongs to the major branch of philosophy known as metaphysics.
Ontologists often try to determine what the categories or highest kinds are and how they form a system of categories that provides an encompassing classification of all entities. Commonly proposed categories include substances, properties, relations, states of affairs and events. These categories are characterized by fundamental ontological concepts, like particularity and universality, abstractness and concreteness or possibility and necessity. Of special interest is the concept of ontological dependence, which determines whether the entities of a category exist on the most fundamental level. Disagreements within ontology are often about whether entities belonging to a certain category exist and, if so, how they are related to other entities.When used as a countable noun, the terms "ontology" and "ontologies" refer not to the science of being but to theories within the science of being. Ontological theories can be divided into various types according to their theoretical commitments. Monocategorical ontologies hold that there is only one basic category, which is rejected by polycategorical ontologies. Hierarchical ontologies assert that some entities exist on a more fundamental level and that other entities depend on them. Flat ontologies, on the other hand, deny such a privileged status to any entity.

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  1. Demystifier

    I Ontology is to quantum theory what hardware is to computation theory

    In interpretations of quantum mechanics there are two types of physicists: those who care about ontology and those who don't. The ontologists, or realists, want to know what is the world made of. The non-realists, on the other hand, think that this question is not relevant to physics. Usually...
  2. entropy1

    I Inference about entanglement ontology

    Suppose particles P1 and P2 are spin entangled in singlet state, then, if someone claims that IF particle P1 is found to be in spin-up state when measured, that THEN particle P2 is in spin-down state, does that follow from the minimal formalism, or is it just an assumption?
  3. Demystifier

    I Exploring the Meaning of Ontology: Easy for Kids, Hard for Quantum Physicists

    Ontology is the easiest and the hardest concept in the field of quantum foundations. It is the easiest because even a child can understand it. When a child asks: "What is the world made of?", she asks about ontology. When you answer: "It's made of atoms" and when she asks "What does the atom...
  4. TheHeraclitus

    Particle ontology and quantum fluctuations

    I have been reading about ontologies in quantum physics recently and I came across Bohmian mechanics. If I understood it correctly BM endorses Particle ontology. Particle ontology claims that point-like particles that move continuously in time are the fundamental building blocks. I know some...
  5. TheHeraclitus

    I Ontology of Causal Dynamical Triangulation

    Also, what does Sabine mean in this video by the sentence: (5:51 in the video) Thank you!
  6. entropy1

    I Ontology of an electron passing through a Stern-Gerlach magnet

    So, as far as I think I understand, an electron that passes through a Stern-Gerlach magnet, will not have a value for its spin until that spin is measured? Does that mean the electron has no position (as given by the SGM) until measured, or that the electron does not even exist until measured?
  7. entropy1

    I Ontology of measurement and correlation

    If a non-commuting measurement is made on a quantum property (like spin), this can be seen as the wavefunction being prepared. So you can't tell if the outcome represents the property, or that the property is prepared. However, if the property is prepared, we can predict the correlation with a...
  8. entropy1

    I QM & Ontology: Why Should We Stay Away?

    I was thinking that QM and QM practicioners tend to stay away from the ontology part of QM, and see the QM framework as useful for predicting measurement outcomes. But if I see the properties of wood or plastic, they are explained by the properties of the particles they are "made up from", and I...
  9. Demystifier

    A The ontology problem of thermal interpretation

    I have already discussed the ontology problem of thermal interpretation (TI) of quantum mechanics (QM) several times in the main thread on TI. The following is supposed to be the final refined version of my argument, so I don't want it to be lost among other posts in the main TI thread...
  10. F

    I What Is the Role of Ontology in the Interpretations of Quantum Mechanics?

    It seems that the word ontology which suppose to be about the most concrete object we can come up with is itself not well defined. Take for example this post Which alludes to primitive ontology as a property and not "what" is actually there(ontology proper) as the ultimate ontology which we...
  11. entropy1

    I Does a measurement setup determine the reality of spin measurement outcomes?

    Summary: If a measurement outcome depends on the measurement setup, is de measured not real or the measurement? If the factual outcome of an electron-spin measurement depends on the orientation of the SG magnet, for instance up or down in one orientation and left or right in the other, does...
  12. Demystifier

    A Copenhagen: Restriction on knowledge or restriction on ontology?

    The title of this thread is motivated by frequent arguments I had with other members here, especially @DarMM and @vanhees71 . The so called "Copenhagen" interpretation of QM, known also as "standard" or "orthodox" interpretation, which is really a wide class of related but different...
  13. entropy1

    Do worlds of MWI ontologically have to exist?

    Is MWI equivalent to a superposition of possible Collapse-worlds? That is, is it equal to a superposition of the possible scenario's given by Collapse Interpretation? Is it imparative that the "worlds" given by MWI all ontologically exist?
  14. M

    I How do I show a skeptic that atoms/molecules actually exist?

    This might be a stupid question so please bear with me. I am having a debate with a friend of mine over the Internet. It is about science. His argument is that although science works (that is the technology part), science cannot actually tell anything about "reality". He sites for example...
  15. T

    B Why is the Existence of a Quantum Field Questioned?

    Are there thoughts as to why there is a quantum field. Does it arise from something more fundamental? Thanks for considering.
  16. G

    I Ontology of wavefunction vs. ontology of electric field

    Hi. Different interpretations of QM have different opinions about the ontology of the wavefunction, i.e. if it really, physically exists or if it is "just" a mathematical tool needed to calculate the outcome of measurements. The QM interpretations comparison table on Wikipedia summarises the...
  17. J

    Time, Ontology & Platonic Reality vs Material Reality

    I’m not sure in what is the best way approach this topic in-order to stay within the forum guidelines but I hope I’ve done so. From the recent moderator actions, this topic it is too far removed from the philosophy of mathematics to be part of that thread. The basic question is whether existence...
  18. P

    Relation between Critical Realism, Ontology and Epistemology

    Hello, I have to present Critical Realsim theory to class. I have been coming across words like Ontology and Epistemology. I made effort to see what those terms are and their relation to critical realism but I couldn't understand it. It talks philosophy. Can some help me to understand in simple...
  19. R

    Relativity and the Heisenberg Ontology

    Is it true that "The dogmas of relativity theory cannot be expected to apply to the consideration of the dynamical process by which reality actually unfolds."?? What does it mean? Physicist Stapp was describing about the Heisenberg ontology and it's possible relativity problem:
  20. S

    Ontology of AdS/CFT classical on the bulk?

    Is it true in AdS/CFT the ontology on the boundary is quantum (whatever that may be), and the ontology in the bulk is classical? If that were true it would be a new "interpretation" of quantum mechanics.
  21. P

    Theories of truth and ontology

    Hey guys, I have been thinking about the problem of mathematical truths. We simply do not know if the things that mathematics deals with really exist or not, yet people still believe that its statements are true and indubitable. Unfortunately, the only truly well-respected theory of truth in the...
  22. V

    String Theory's implications of ontology

    Given that string theory purports some 10th dimensional ontology, does it refute creation? Or make it unnecessary? I personally do not believe that the Universe is a product of intelligent design, but I'd like to explore the concepts of string theory and its relation to the origin of things(and...
  23. J

    Science,Knowledge, and Ontology

    First off, I apologize for my lack of being able to pose this question/ line for discussion in as clear terms as possible. What I essentially want to converse about is the question "To what extent is Scientifc Ontology necessary for the practice of Science?". Of course, their are various...
  24. A

    Is Quantum Physics an Epistemology or an Ontology?

    "The conception of objective reality of the elementary particles has thus evaporated not into the cloud of some obscure new reality concept but into the transparent clarity of a mathematics that represents no longer the behaviour of particles but rather our knowledge of this behaviour.''...
  25. J

    Can God's Existence be Proven Subjectively but not Objectively?

    The point of this thread is to post my own currently developed philosophy and see how it holds to everyone's scrutiny. I'm an agnostic theist. I personally believe that God exists, and that objectively, humans can't know if God exists or not. I believe there are two types of truth, subjective...
  26. V

    What is the ontology of general relativity ?

    What is the "ontology" of general relativity ? Hi, First of all, though I know some GR, I'm far from an expert on it. I used to think of the "ontology" of GR as being a 4-dimensional manifold with a metric connection on it, but apparently that doesn't fly, because of the "hole argument"...
  27. loseyourname

    Discussing Deleuzian Ontology: Implications for Death & Philosophy

    So we're discussing an article on Deleuze by Manuel DeLanda in a seminar of mine. We were given a question to answer and bring to class to start discussion with, and I've copied and pasted what I wrote into this post. I don't know if anybody is interested in discussing this topic here, but I...
  28. M

    Can physics fully explain consciousness?

    Does modern physics need to expand its current ontology to cater for the existence of qualia and consciousness, or is it possible that these phenomena could be explained entirely within our current physical framework of matter, energy, space and time (or possibly strings)?
  29. M

    What is the Role of Ontology in Epistemic Differences and Entity Connections?

    Why does the epistemic differences established by mind-body distinctions necessitate an ontological divide? What is the defining difference between ontologies? How could two entities, from separate ontologies, ever be connected? Any related comments or answers are, as always, greatly...
  30. C

    Do String Theory Dualities Challenge Traditional Ontology?

    In a recent post in his blog, Woit comments on a philosophy of science article by a philosopher who claims that the dualities in string theory imply the "dissolution of the ontological object". His claim is that because the dualities in string theory can describe two different sorts of...
  31. marcus

    Ontology: what's really there

    In the history of physics there are moments of crisis now and then when questions of ontology get confronted. Mostly ontology is ignored and it is business as usual (the business is largely predicting experiment outcomes) without worry about what is really there. Ontology comes from the greek...
  32. marlon

    Why should the question of ontology and epistemology matter to us?

    Hello, everyone... This is my first post here and i need your philosophy-help. I know the standard (you know àlla Wikipedia) definitions of ontology and epistemology. What i need to know is if my example is right here. Please feel free to comment as much as you want. In ontology you can...
  33. P

    What are the Limitations of Purely Logical Arguments in the Context of Ontology?

    You are showing the limitations of your understanding.