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Reduction to Open Individualism

by Iacopo Vettori - September 2016

Chapter 2: Criticism of the identity concept applied to objects

6. From a reductionist point of view, the identity of generic objects is reducible to some material or structural characteristics. Therefore, we have to consider two groups of theories: those that eventually reduce identity to something material, and those that eventually reduce identity to something structural.

7. The theories that reduce identity to something material presuppose that material objects have some “intrinsic identity” that is not structural. Because all material objects are composed of parts, we have to face the paradox of the ship of Theseus: if we gradually change the components of a complex object, we end up having a brand-new object with none of its original components. The original paradox speaks about the mythological ship of Theseus, the first ship ever built, of which it was said that it was conserved by the Athenians and maintained over time by changing out the parts that had deteriorated until no original parts were still in place. If we think that the identity of objects does not depend on their structure, but on the intrinsic identity of something material, we must conclude that the complex object has lost its original identity. The identity of complex objects depends on the identity of their component objects. Reasoning in this way, we quickly find ourselves reduced to considering the intrinsic identity of each subatomic elementary particle.

8. Because we are discussing the identity of objects as the basis of the personal identity concept, we must note that we continuously exchange the matter of our body, literally with every breath we take. A common saying with some scientific grounding is that in seven years we change all the matter that constitutes our body. For this reason, reductionists that support this theory have to acknowledge that despite what we believe, we do not have the same personal identity that we had seven years ago. This does not mean that our body has grown older in seven years; this means that we are actually another person, believing that we are the same person only because we have inherited the memories of the different person who existed seven years ago with a body constituted of completely different matter from the one we have today.

9. Even suspending our judgement about our personal identity, and returning to reasoning about the identity of the objects, we have to face another problem. The question comes from the fact that that physics says that elementary particles have some measurable properties, but have no intrinsic identity. They are indistinguishable. And if we still imagine that they may have some hidden univocal property to which we may anchor their identity, then we are embracing a theory that cannot contend with dualist theories on the grounds of unfalsifiability, because it is also unfalsifiable. Some might think that the identity of a particle can be given by its position in space-time, which has to be unique. Actually, these are geometric properties that are best suited to the concept of identity based on structure, discussed next. Keep in mind that space-time coordinates are not absolute; they are always relative to some reference system.

10. The fact that elementary particles are indistinguishable is difficult to accept: our common sense suggests that each particle has its own position, and as we can trace its position in space, we can be sure that it has some identity that persists in time. But modern physics says that reality is much more complicated than that. We may have successive detections of particles but nothing guarantees that the particle is the very same as before. The equations to compute the positions of particles regard them as a wave and give as a result the probability of all the possible new positions. Regarding the particle detected in a second place as the very same particle that was detected in a first place is an arbitrary generalization of our thinking, but is not based on any physical truth. Quantum physics regards all the particles as continually appearing and disappearing in a so-called “quantum foam” of virtual particles. We should think of particles as the localized counterpart of a given energy packet, not as little material marbles. We can still imagine associating an identity with each energy packet, but the ground becomes slippery here for an identity concept based on matter, because these packets are local thickenings of the total energy of the universe. A good article by Meinard Kuhlmann published by Scientific American in August 2013 explains these experimental problems: . Studying the matter at the extremes of our knowledge, we end up with equations and packets of energy that cannot help in supporting the concept of identity based on something material. The world is made of particles no more material than bubbles on the surface of boiling water. This leads us to regard identity as something that derives from structure.

11. According to Derek Parfit, your personal identity remains the same (and therefore you remain you) as long as your psychological traits are sufficiently similar to the ones you had before. In the reductionist view, these psychological traits are mapped physically to a configuration of neurons in your brain. So, in this view, your personal identity depends on the identity of an object that is identified as something structural: the identity of a brain with the neuronal configuration that implements your psychological traits.

12. It is possible to say that the identity of a brain is based on its capacity to generate thoughts. We can say that a brain itself has no identity, but it acquires an identity only when it is functioning. This can be regarded as a more abstract level of structural identity, but actually is not based on the identity of an object, but on a property of that object that makes it a subject. This will be discussed in more detail later, once we have seen that the concept of identity when referring to objects is not a good one to base the concept of personal identity on. Here, we have to notice that the concept of “functioning brain” has meaning only from a perspective of sentience, because it expresses the capacity of the brain to generate a mind that we know exists only by our direct experience, but is not deducible by simple physical observation: we are able to observe only the physical counterparts of the brain activity, but the notion that that activity generates a mind is proven only by our personal direct experience of our own mind.

13. Because we discuss the identity of objects in order to use it to define personal identity, we have to face the problem that because identity based on structure is not linked to some specific bunch of matter, in principle we could build many brains having the very same structure and therefore generate many numerically different minds with the very same personal identity. Parfit thinks that if your body is destroyed and then built again in a different place, replicating exactly the same original structure, your personal identity would be preserved. But if your body is replicated without destroying the original body, Parfit thinks that the original personal identity may not be preserved even in the original body. To avoid the possibility of two physically separated bodies having the same personal identity, Parfit needs to introduce a clause that specifies that personal identity is preserved as long as there exists only a single physical brain at a given time with the required structural characteristics. This is what Daniel Kolak calls a “metaphysical epicycle”, and it raises more problems than it solves. This clause implies that the existence somewhere in space of a copy of myself influences my personal identity, and therefore that my personal identity is determined not only by my inner structure, but also by the outer structure of the world around me.

14. Actually, this problem also applies when we reason about bare objects. In our daily life, we know that two identical objects are not really identical: if we could check them atom-by-atom, we would discover many little differences. Notwithstanding this, we can imagine having two objects of macroscopic dimensions, let’s says two salt crystals, that are exactly identical to each other even when compared at the level of atoms. In this case, we would not say that because they have the same structure, they have the same identity. We would make a distinction, talking about “the one on the left” and “the one on the right”. This means that the outer environment is playing a part in defining the identity of the two objects. But if we limit the definition to a finite environment, then recreating a copy of the environment would once more introduce an ambiguity in the definition. To avoid definitively any ambiguities in the definition of the identity of an object, we have to consider an environment so vast that it is not possible to copy it, to make sure that it is unambiguous throughout the whole universe. This is the same as the case we suggested before, in criticizing the concept of identity based on matter, about the proposal to link the identity of each elementary particle to its position in space-time. We end up needing to consider the whole universe in order to define the identity of its elementary particles.

15. In accordance with all these considerations, it turns out that the identity of every object, and therefore, if we are reductionists, the personal identity of each human being, is determined not only by its inner structure, but also by the structure of the surrounding environment. The identity of an object is not an intrinsic property that it has a priori, but rather it can be defined unambiguously only by considering the environment containing the object, and to avoid any ambiguity this environment has to be expanded to include the whole universe.

16. The parts of the universe to which we assign separate identities are arbitrary. For example, two separate islands can be considered to have two different identities, but if the level of the sea decreases, they can become a single island, with a different identity than the original two, without any change in their inner structure. It is just a matter of practical convention to regard them as two objects instead of a single greater geographical region, or as just parts of the planet Earth. This also applies to objects that seem more definite, such as two crystals or two clocks. We are comfortable with this because objects appear spatially separated. Actually, this geometrical condition simplifies our communication conventions, but we could assign them other identities in a different way, without any loss in terms of physical reality. The reason that it appears natural to assign a different identity to different objects like two clocks is that each of these objects may be used to execute the task of keeping time. This task is meaningful for us, because we are sentient observers who know that some objects can be used to achieve a goal, but still the fact that we regard the clock as having an identity is a decision that we make arbitrarily.

17. From a strictly physical point of view, all physical objects are temporary structures made of energy packets tossed into the quantum foam. We have to conclude that the identity of objects is always reducible to a communication convention and that it has no absolute meaning. Considering all the objects as geometrical parts of the whole universe actually defers the problem of the definition of the identity of objects to the identity of the universe. But the only way to define the identity of the whole universe is to describe its inner structure, and this causes the definition of all the identities to become circular.

18. Once the concept of identity of objects is lost, even the difference between the concepts of “type” and “instances” of objects vanishes. The instance of an object can be regarded as the actualization-with-a-unique-identity of a type definition. Once the unique identity is deferred to the whole universe, which has no further container object, this unique identity become useless, and the definition of an unidentified actualization of the type corresponds with the definition of the type. It is important to remark that in considering the universe as a whole, I mean that it has no exchange of information with anything else. If we ever discover some forces that are inducted by a parallel universe, we should consider both our universe and the parallel universe, or even a bigger multiverse, to again be “the whole universe”. As the concept of identity vanishes when applied to the whole universe, so also the difference between the theoretical existence of the universe and the actualization of the universe that we experience vanishes. I mean that we may think of ourselves as experiencing directly the type of the universe, instead of the actualization of one instance of that type. This will be discussed again later when speaking about the General Existential Problem.


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