Metaphysical Problems
Metaphysics is the branch of philosophy that studies the ultimate constituents of reality. Metaphysics concerns itself with two types of inquiry. The first aims to be the most general investigation into the nature of reality. The second type of inquiry seeks to uncover what is ultimately real, frequently offering answers in sharp contrast to our everyday experiences of the world.
As understood in these two ways, the central concern of metaphysics is with what existence is. Metaphysics is closely related to ontology, which asks questions like "What is existence?" and "What type of thing exists?" Ontology is the study of what exists. It is the philosophical study of existence (where existence means everything that exists).
Philosophers have attempted to understand what exists by naming, categorizing, and grouping things, by ordering or prioritizing everything, and so on. The system that results from a particular philosopher's inquiry into existence is also called his or her ontology.
To the question of what type of thing exists, a particular school of thought in philosophy, known as nihilism, holds that nothing exists. The nihilist can claim, descriptively, that in fact nothing really exists (for instance, that there is no God, or no, or that everything is just illusions and there is nothing real behind them). On the other hand, a nihilist can claim prescriptively that there ought not to be anything, that nothing is good, and so we ought to undo everything.
Another school of thought, known as materialism, holds that all that exists are material or physical things. It is a theory that regards matter and its various guises as constituting the universe and all phenomena, including those of the mind, as caused by material agencies.
Contrastively, idealism maintains that everything that exists exists in the minds of human beings or in the minds of God. In epistemology, idealism is an anti-realist theory of perception that holds that knowledge is derived from ideas. This version of anti-realism holds that reality consists of only minds and ideas. Eliminative idealists, for instance, hold that there is no such thing as material objects; that is, material objects are nothing but experiences and ideas in our minds. Reductive idealists, on the other hand, hold that there are material objects, but they are nothing other than complexes of experience.
Metaphysics Problems
However, since metaphysics is concerned with the ultimate constituents of reality, an influential view of reality is that it consists of things and their properties (individual things, often called particulars, and properties, often called universals).
1. The Problem of Universal (Non-Concrete, Abstract) versus Particular (Concrete)
A pair of related metaphysical problems consist of the difficulty of determining whether all objects are concrete or particular things, or more specifically, whether some objects are non-concrete or abstract, and if so, whether some of them are universal.
For instance, if a nonexistent object such as a unicorn did exist, it would exist as a concrete, particular thing, just as a horse actually does. Like a horse, it would exist in both space and time. But some putative objects are abstract, in that if they are real, they are timeless and unchangeable.
Numbers, for example, number five, and sets or classes of things might be deemed abstract because the issue of whether they will undergo any change or whether they come into existence or will cease to exist does not arise. Yet they seem to be particular in that each seems to be such that there can be only one of them. There can be only one number five (though there may be many groups of five things) and only one class of all dogs.
To buttress the above viewpoint, Bertrand Russell explains that the question of what justice is requires considering one or two just acts with a view to discovering what they have in common. For him, they must all, in some sense, possess a common nature, which will be found in whatever is just and in nothing else. This common nature, by virtue of which they are all just, will be justice itself, the pure essence, the admixture of which with the facts of ordinary life produces the multiplicity of just acts.
Entities or objects that can have many instances of particular things have been termed universals. A distinctive feature of particulars is that they cannot be in more than one place at a given time, whereas universals are capable of being wholly present in more than one place at a given time. Another distinctive mark of particulars is that, while a particular instantiates properties and relations, nothing instantiates a particular. Since a particular is not instantiated by another thing, it is sometimes said to exist 'in' itself, whereas a universal exists 'in' something else.
Let's look at this example. Suppose you are looking at five blue balls—five different particular things of exactly the same color. The difference you see is grounded in particularity, in the fact that each ball differs from every other by virtue of being a different particular thing. But as the realist would argue, sameness is as undeniably real as difference and thus must be equally well-grounded, 'a grounding it would have only if a single entity (blueness) had an instance in each ball'.
If the position of the realist is right, then reality includes not only particular things but also general things or universals, such as the blue color quality. But a nominalist would argue that realism is not correct and that there are no universals. A nominalist would argue instead that the sameness of color exhibited by the five balls is not due to a single entity having an instance in each ball but to nothing more than the fact that each ball resembles the others in color. The fact that the balls resemble each other in color must be acknowledged on any account.
Whereas the realist contends that the resemblance is to be explained by the presence of a single entity having an instance in each particular, the nominalist contends that the resemblance is basic, that is, not explicable by appeal to anything more fundamental.
Those who believe in universals are called realists, while those who do not are called nominalists. Realism, as it concerns universals, is the doctrine that universals have a real, objective existence. Nominalism is the doctrine that abstract words or universals do not represent objectively existing entities and that universals are only names applied to individual physical particulars that alone exist objectively.
Another metaphysical problem is that of the relationship between the mind and the body. How connected are they?
2. The Mind/Body Problem
Two fundamental questions are often asked in the mind-body controversy. There is the ontological question of what mental and physical states are and the causal question of whether and how physical states influence mental states and vice versa.
Different aspects of the mind-body problem arise for different aspects of the mind, such as consciousness, intentionality, and the self.
Howard Robinson identifies some of these problems as:
- The problem of consciousness: What is consciousness? How is it related to the brain and the body?
- The problem of intentionality: What is intentionality? How is it related to the brain and the body?
- The problem of the self: What is the self? How is it related to the brain and the body? And
- The problem of embodiment: What is it like for the mind to be housed in a body? What does it mean for a body to belong to a particular subject?
In an attempt to answer the above questions, the mind is conceived as an un-extended and immaterial mental substance, while the body is a corporal substance extended in time and space.
In philosophical parlance, therefore, this position, technically referred to as dualism, posits that man is composed of two entities: a material thing (his body) and a non-spatio-temporal entity (his mind). The dualist views the mental and the physical as real entities, and neither can be assimilated into the other. Monism, on the other hand, is the view that man is composed of only one entity, either the mind or the body, but not both.
The seemingly intractable nature of these problems has given rise to many different philosophical views. Descartes (a dualist and an interactionist) is of the view that human beings are composed of two entities: the mind and the body, and they mutually interact in a single system, which he calls the pineal gland.
Interactionism, therefore, is the view that mind and body, or mental and physical events, causally influence each other. This is commonly believed by many people because it appears to be a feature of everyday experience. The physical world influences my experience through my senses, and I often react behaviorally to those experiences. My thinking, too, influences my speech and my actions.
Given this interactionist position of two different entities having effect on each other, one may then demand of Descartes to tell us how possible it is for the un-extended to have effect on the extended; for, according to Elizabeth Armstrong and Peter Geach, "contact seems incompatible with a thing being immaterial.".
Property dualism maintains that certain states or processes occurring in the brain have two aspects or properties: a physical aspect and a mental aspect. To illustrate, as you place a piece of sweet in your mouth and experience its taste, the state or process in the affected portion of your brain has the physical property of being an electrochemical disturbance but also the mental property of being a distinctive flavor.
There is only a single event or process involved, but it has quite different properties or aspects. The brain is, therefore, not a purely physical system. Some of the processes that take place in the brain have not only an external physical aspect that can be publicly observed, perhaps by surgically exposing someone's brain or monitoring its activity with instruments, but also an inner mental aspect that is observable only by the person whose brain it happens to be.
Other variants of dualism, like occasionalism, legislated God into existence as what one may refer to as the mind-body regulator in order to explain the mind-body correlation. Thus, when I hit my foot against a hard object, God, on Malebranche's exposition, intervenes so that I feel pain. Leibniz's psycho-physical parallelism, on the other hand, submits that mental and physical events are like two parallel lines eternally drawn by God or like two clocks, perfectly synchronized by God, such that when, for example, X is pricked by a sharp object, the parallel reaction is that X feels pain.
The creation of, and appeal to, superfluous entities by these dualist theories no doubt renders them implausible. Such correlation laws or superfluous entities relating objectively determinable phenomena with what is otherwise determinable have been described by Herbert Feigl as "nomological danglers.".
This insuperable objection against dualism takes us to the philosophical monists' attempt to resolve the mind-body problem. Paradigmatic of the monists' attempts at epiphenomenalism and central state materialism.
Both theories are materialist and monist in orientation in that they attempt to explain all mental events or all mental occurrences in terms of the observable changes or processes in the brain. Central state materialism, for instance, maintains that every mental state is identical to some state of the brain or central nervous system.
The idea that we are purely material beings was proposed many decades ago by the ancient Greek philosophers Leucippus and Democritus. Many philosophers and scientists have held that the mind is nothing but the brain. Francis Crick, for instance, opines that "the astonishing hypothesis is that you, your joys and your sorrows, your memories and ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules.".
Functionalism attempts to salvage the materialist position. It maintains that mental states are functional states, that is, states whose mental natures are constituted by their causal relations. A mental state is essentially one with a particular kind of cause, say, a sensory input that leads to a particular kind of effect, say, a behavioral output. The particular kind of cause or effect of a given mental state may be some other kind of mental state, and the totality of the causal relations into which that given mental state enters is called its 'causal' or 'functional' role.
Epiphenomenalism is the view that mental events are caused by physical events in the brain but have no effects on any physical events. Behavior is caused by muscles that contract upon receiving neural impulses, and neural impulses are generated by input from other neurons or from sense organs. On the epiphenomenalist view, mental events play no causal role in this process.
This response, ascribing causal impotency to the mental, however, appears implausible. For example, when I experience or entertain the thought of eating fried rice, I sometimes salivate, and sometimes, when I am angry, I break objects nearby, such that it appears incredible to suggest that the mental cannot cause the physical. This remains a problem.
3. How do we explain God's existence?
The question of explaining whether God exists or not has always remained a metaphysical question and problem. There are a great number of views about God, some of which will be examined here. Polytheism, the belief that there exists a plurality of personal gods, is common among tribal people and is clearly present in Greek and Nordic mythologies. A variation of polytheism is dualism.
The dualist holds that there is a plurality of only two gods who are opposed to each other. Usually, one god is seen as good and the other is seen as evil. Henotheism also recognizes a plurality of gods, but the henotheist restricts his allegiance to one god, either because he sees that god in some way as superior to the others or simply because that god is the god of his own tribe or people.
Monotheism, often simply abbreviated as theism, holds that only one God exists. God is seen as a personal being, supreme in power, knowledge, and moral worth. He created all other existing beings out of nothing. A variation of monotheism is deism. Deism is the belief in one God, like the theist, but that this God does not or cannot involve Himself in His creation.
Pantheism, often associated with some varieties of Hinduism and other Eastern religions but not uncommon in the West, holds that it is not proper to think of God as a personal being, or, according to some of them, as a being of any kind. Such concepts are thought to be too limiting for God, who must ultimately be understood as identical with nature or the universe as a whole.
The universe is, in some sense, God, but God is more than the universe. Absolute monism can be seen as a variation of pantheism or panentheism. The absolute monist holds that God is an absolute unity that is somehow manifested in a less-than-fully-real world of apparent plurality.
There are also views that reject any belief in God. Agnosticism holds that the truth about God cannot be or is not known and that people should therefore suspend judgment on the question. Atheism goes further and actually denies the existence of God. Naturalism is a worldview that entails atheism. The naturalists do not believe in any supernatural realm behind nature; they believe rather that the natural order of things simply exists "on its own.".