Philosophical realism

Contemporary philosophical realism is the belief that our reality, or some aspect of it, is ontologically independent of our conceptual schemes, linguistic practices, beliefs, etc. Realism may be spoken of with respect to other minds, the past, the future, universals, mathematical entities (such as natural numbers), moral categories, the material world, or even thought. Realism can also be promoted in an unqualified sense, in which case it asserts the mind-independent existence of a visible world, as opposed to idealism, skepticism and solipsism. Philosophers who profess realism state that truth consists in the mind's correspondence to reality.

Realists tend to believe that whatever we believe now is only an approximation of reality and that every new observation brings us closer to understanding reality.^[1] In its Kantian sense, realism is contrasted with idealism. In a contemporary sense, realism is contrasted with anti-realism, primarily in the philosophy of science.

History

The oldest use of the term "realism" appears in medieval scholastic interpretations and adaptations of Greek philosophy. Here, however, it is a Platonic realism developed out of debates over the problem of universals. Universals are terms or properties that can be applied to many things, such as "red", "beauty", "five", or "dog". Realism in this context, contrasted with conceptualism and nominalism, holds that such universals really exist, independently and somehow prior to the world. Moderate Realism holds that they exist, but only insofar as they are instantiated in specific things; they do not exist separately from the specific thing. Conceptualism holds that they exist, but only in the mind, while nominalism holds that universals do not "exist" at all but are no more than words (flatus voci) that describe specific objects.

Platonic realism

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Platonic realism is a philosophical term usually used to refer to the idea of realism regarding the existence of universals or abstract objects after the Greek philosopher Plato (c. 427–c. 347 BC), a student of Socrates. As universals were considered by Plato to be ideal forms, this stance is confusingly also called Platonic idealism. This should not be confused with Idealism, as presented by philosophers such as George Berkeley: as Platonic abstractions are not spacial, temporal, or mental they are not compatible with the later Idealism's emphasis on mental existence. Plato's Forms include numbers and geometrical figures, making them a theory of mathematical realism; they also include the Form of the Good, making them in addition a theory of ethical realism.

The Scottish School of Common Sense Realism

Main article: Common Sense Realism

Scottish Common Sense Realism is a school of philosophy that sought to defend naive realism against philosophical paradox and scepticism, arguing that matters of common sense are within the reach of common understanding and that common-sense beliefs even govern the lives and thoughts of those who hold non-commonsensical beliefs. It originated in the ideas of the most prominent members of the Scottish School of Common Sense, Thomas Reid, Adam Ferguson and Dugald Stewart, during the 18th century Scottish Enlightenment and flourished in the late 18th and early 19th centuries in Scotland and America.

Its roots can be found in responses to such philosophers as John Locke, George Berkeley and David Hume. The approach was a response to the "ideal system" that began with Descartes' concept of the limitations of sense experience and led Locke and Hume to a skepticism that called religion and the evidence of the senses equally into question. The common sense realists found skepticism to be absurd and so contrary to common experience that it had to be rejected. They taught that ordinary experiences provide intuitively certain assurance of the existence of the self, of real objects that could be seen and felt and of certain "first principles" upon which sound morality and religious beliefs could be established. Its basic principle was enunciated by its founder and greatest figure, Thomas Reid:

"If there are certain principles, as I think there are, which the constitution of our nature leads us to believe, and which we are under a necessity to take for granted in the common concerns of life, without being able to give a reason for them--these are what we call the principles of common sense; and what is manifestly contrary to them, is what we call absurd.".^[2]

Common sense realists tend to oppose indirect realism and representationalism, which they see as leading to skepticism.

Naive realism

Naïve realism, also known as direct realism is a philosophy of mind rooted in a common sense theory of perception that claims that the senses provide us with direct awareness of the external world. In contrast, some forms of idealism assert that no world exists apart from mind-dependent ideas and some forms of skepticism say we cannot trust our senses. The realist view is that objects are composed of matter, occupy space and have properties, such as size, shape, texture, smell, taste and colour, that are usually perceived correctly. We perceive them as they really are. Objects obey the laws of physics and retain all their properties whether or not there is anyone to observe them.^[3]

Scientific realism

Scientific realism is, at the most general level, the view that the world described by science is the real world, as it is, independent of what we might take it to be. Within philosophy of science, it is often framed as an answer to the question "how is the success of science to be explained?" The debate over what the success of science involves centers primarily on the status of unobservable entities apparently talked about by scientific theories. Generally, those who are scientific realists assert that one can make reliable claims about unobservables (viz., that they have the same ontological status) as observables. Analytical philosophers generally have a commitment to scientific realism, in the sense of regarding the scientific method as a reliable guide to the nature of reality. The main alternative to scientific realism is instrumentalism.

In practice

Both these disputes are often carried out relative to some specific area: one might, for example, be a realist about physical matter but an anti-realist about ethics. The high necessity of specifying the area in which the claim is made has been increasingly acknowledged^{[citation needed]} in recent years.

Increasingly these last disputes, too, are rejected as misleading, and some philosophers prefer to call the kind of realism espoused there "metaphysical realism," and eschew the whole debate in favour of simple "naturalism" or "natural realism", which is not so much a theory as the position that these debates are ill-conceived if not incoherent, and that there is no more to deciding what is really real than simply taking our words at face value.

Some realist philosophers prefer deflationary theories of truth to more traditional correspondence accounts.

Realism in logic and mathematics

Further information: Philosophy of mathematics

Mathematical realism, like realism in general, holds that mathematical entities exist independently of the human mind. Thus humans do not invent mathematics, but rather discover it, and any other intelligent beings in the universe would presumably do the same. In this point of view, there is really one sort of mathematics that can be discovered: Triangles, for example, are real entities, not the creations of the human mind.

Many working mathematicians have been mathematical realists; they see themselves as discoverers of naturally occurring objects. Examples include Paul Erdős and Kurt Gödel. Gödel believed in an objective mathematical reality that could be perceived in a manner analogous to sense perception. Certain principles (e.g., for any two objects, there is a collection of objects consisting of precisely those two objects) could be directly seen to be true, but some conjectures, like the continuum hypothesis, might prove undecidable just on the basis of such principles. Gödel suggested that quasi-empirical methodology could be used to provide sufficient evidence to be able to reasonably assume such a conjecture.

Within realism, there are distinctions depending on what sort of existence one takes mathematical entities to have, and how we know about them.

Alternatives to mathematical realism include formalism and fictionalism.

Critics

• Constructivist epistemology

Moral Realism

Moral realism is the meta-ethical view which claims that:

1. Ethical sentences express propositions.
2. Some such propositions are true.
3. Those propositions are made true by objective features of the world, independent of subjective opinion.

This makes moral realism a non-nihilist form of cognitivism. Moral realism stands in opposition to all forms of moral anti-realism, including ethical subjectivism (which denies that moral propositions refer to objective facts), error theory (which denies that any moral propositions are true), and non-cognitivism (which denies that moral sentences express propositions at all). Within moral realism, the two main subdivisions are ethical naturalism and ethical non-naturalism.

Time and space

Main article: Philosophy of space and time

A traditional realist position in ontology is that time and space have existence apart from the human mind. Idealists deny or doubt the existence of objects independent of the mind. Some anti-realists whose ontological position is that objects outside the mind do exist, nevertheless doubt the independent existence of time and space.

As well as differing about the reality of time as a whole, metaphysical theories of time can differ in their ascriptions of reality to the past, present and future separately.

• Presentism holds that the past and future are unreal, and only an ever changing present is real.
• The block universe theory, also known as Eternalism, holds that past, present and future are all real, but the passage of time is an illusion. It is often said to have a scientific basis in relativity.
• The growing block universe theory holds that past and present are real, but the future is not.

Modal realism

Modal realism is the view, notably propounded by David Kellogg Lewis, that all possible worlds are as real as the actual world. It is based on the following tenets: possible worlds exist; possible worlds are not different in kind from the actual world; possible worlds are irreducible entities; the term actual in actual world is indexical, i.e. any subject can declare their world to be the actual one, much as they label the place they are "here" and the time they are "now".

See also

• Analytic philosophy
• Critical realism
• Epistemological realism
• Legal realism
• Moderate realism
• Objectivism
• Philosophy of social science
• Principle of bivalence
• Problem of future contingents
• Truth-value link realism

Notes

1. ^ Blackburn p. 188
2. ^ Cuneo and Woudenberg, eds. The Cambridge companion to Thomas Reid (2004) p 85
3. ^ Naïve Realism, Theory of Knowledge.com.

References

• Blackburn, Simon (2005). Truth: A Guide. Oxford University Press, Inc. ISBN 0-19-516824-0. 

External links

• Stanford Encyclopedia of Philosophy entry
• An experimental test of non-local realism. Physics research paper in Nature which gives negative experimental results for certain classes of realism in the sense of physics.