The Theory of Forms or Theory of Ideas, also known as Platonic idealism or Platonic realism, is a philosophical theory credited to the Classical Greek philosopher Plato.
A major concept in metaphysics, the theory suggests that the physical world is not as real or true as Forms (or Ideas, typically capitalized):"Chapter 28: Form" of The Great Ideas: A Syntopicon of Great Books of the Western World (Vol. II). Encyclopædia Britannica (1952), pp. 526–542. This source states that Form or Idea get capitalized according to this convention when they refer "to that which is separate from the characteristics of material things and from the ideas in our mind". Thus, capitalization of the word "Idea" here is meant to show that it is a special technical term in philosophy, rather than the ordinary English word "idea". the timeless, absolute, non-physical, and unchangeable essences of all things, which objects and matter in the physical world merely participate in, imitate, or resemble.Meinwald, Constance C. (updated Sept. 2024). "Plato: Forms as perfect exemplars". Britannica. In other words, Forms are various abstract ideals that exist even outside of human minds and that constitute the basis of reality. Thus, Plato's Theory of Forms is a type of philosophical realism, asserting that certain ideas are literally real, and a type of idealism, asserting that reality is fundamentally composed of ideas, or abstract objects.
Plato describes these entities only through the characters (primarily Socrates) in his dialogues, who sometimes suggest that these Forms are the only objects of study that can provide knowledge (as opposed to mere belief or opinion), and at other times contest the very existence of the Forms. The theory remains a general point of controversy in philosophy; nonetheless, it is considered to be a classical solution to the problem of universals.
Etymology Referring to Forms, Plato used a number of Ancient Greek terms that mainly relate to vision, sight, and appearance, including (; from a root meaning to see), a word that precedes attested philosophical usage. Plato uses these aspects of sight and appearance in his dialogues to explain his Forms, including the supreme one: the Form of the Good. Other terms include () meaning "visible form", and the related terms () meaning "shape", and () meaning "appearances", from () meaning "shine", ultimately from Indo-European *bʰeh₂- or *bhā-. The original meanings of these terms remained stable over the centuries before the beginning of Western philosophy, at which time they became equivocal, acquiring additional specialized philosophic meanings. Plato used the terms and interchangeably.
Pre-Socratic philosophy The pre-Socratic philosophers, ancient Greek thinkers who predated Plato and his mentor (Socrates), noted that appearances change, and they began to ask what the thing that changes "really" is. If something changes, what is it that remains to ground the thing's identity? The answer was substance, which stands under the changes and is the actually existing thing being seen. The status of appearances now came into question, including how the appearance is related to the substance. For instance, the earliest known pre-Socratic philosopher, Thales, argued that the fundamental substance of which all things are made is water.
Scriptures written by Pythagoras, another pre-Socratic philosopher, suggest that he developed an earlier theory similar to Plato's Forms. For Pythagoras, like Plato, the substance or essence of all things was not something physical (like water) but rather something abstract. However, Pythagoras' theory was much narrower than Plato's, proposing that the non-physical and timeless essences that compose the physical world are specifically numbers, whereas Plato conceived of his Forms as a vast array of intangible ideals.
Theory The Forms are expounded in Plato's dialogues, wherein it is proposed that every kind or quality—goodness, justice, equality, beds, horses, etc.—has a corresponding Form; these Forms are held to be that which is "really real", whereas sensible phenomena (i.e., those perceived through the senses) are merely their "shadows" or imitations: momentary portrayals of the Form, as realized under various circumstances. Thus, for Plato, Forms are more real than the objects of our everyday experience: though Forms are timeless and unchanging, physical things are in constant flux; where Forms are unqualified perfection, physical things are qualified and conditioned.Kidder, D. S. and Oppenheim, N. D. (2006), The Intellectual Devotional, p. 27, Borders Group, Inc, Ann Arbor, .
Form answers the question, "What is that, essentially?" That is, a Form is something like the essence of a thing or quality: that without which the thing would not be the kind of thing that it is. For example, there are countless and disparate tables in the world, but the "Form of Table" is that essence of "tableness" in virtue of which each particular table is a table.Cratylus 389: "For neither does every smith, although he may be making the same instrument for the same purpose, make them all of the same iron. The form must be the same, but the material may vary ...." Alternatively, or in addition, a Form may be understood as a sort of objective "blueprint":For example, Timaeus 28a–b: "The work of the artificer, whenever he looks to the unchangeable and fashions the form and nature of his work after an unchangeable pattern, must necessarily be made fair and perfect ..." the perfect and unchanging paradigm for some kind, quality, or mathematical object.
Given that such Forms are exactly the same whenever anyone chooses to consider them (as it is difficult to imagine what it would even mean for there to be a change in the very geometrical ideal of, say, the isosceles triangle)—i.e., time only affects the observer, not the ideal—and are similarly unaffected by location, Plato obtained what was perhaps his most original result, qua Forms: that they are aspatial (transcendent to space) and atemporal (transcendent to time). Neither sempiternal (enduring for all time) nor mortal, they transcend time altogether;The creation of the universe is the creation of time: "For there were no days and nights and months and years ... but when he (God) constructed the heaven, he created them also." (Timaeus 37d–e.) For the creation God used "the pattern of the unchangeable," which is "that which is eternal" (Tim. 29a). Therefore, "eternal" (to aïdion, "the everlasting"), as applied to Form, means "atemporal". similarly, they have no spatial dimensions—and thus neither any orientation in space—nor (like the point) do they possess locations.
Though Forms are non-physical, neither are they merely within the mind (i.e., they are real in the strictest sense of the word). Indeed, according to the Platonic understanding, the world of Form is—as well as transcendent to the sensible world—the essential basis both thereof, and of true (stable, enduring) knowledge.For example, Theaetetus 185d–e: "...the mind in itself is its own instrument for contemplating the common terms that apply to everything." "Common terms" here refers to existence, non-existence, likeness, unlikeness, sameness, difference, unity, and number. Conversely, sensible particulars—being changeable, subject-relative, and tied to unreliable perception—provide an apt basis for only opinion.Gk. , dóxa; see e.g. Republic V.479d–480a.
For example, consider a triangle drawn upon a blackboard: such a triangle, as drawn by a human hand, is necessarily imperfect—as will be all earthly triangles—so whence the recognition thereof as approximations of mathematically ideal triangles (which we have never seen)? For Plato, it is the intelligibility of the "Form of Triangle" that allows us to know the drawing on the chalkboard as a triangle. Similarly, the Form of the circle enables us to draw, define, speak, and write about particular circles—and to recognize and understand the ways in which they fall short of the ideal—though a perfect circle cannot be encountered or perceived by the senses.
For the Platonist, then, the idea of the perfect circle is discovered, not invented—the Form itself exists eternally, regardless of whether it is instantiated or cognized. It follows that the same would go for the Form of Beauty, and indeed for all Forms.
Intelligible realm and separation of the Forms Plato often invokes poetic language—particularly in the Phaedo, Republic, and Phaedrus—to illustrate the mode in which the Forms are said to exist. Near the end of the Phaedo, for example, Plato describes the world of Forms as a pristine region of the physical universe located above the surface of the Earth. In the Phaedrus, the Forms are in a "place beyond heaven" (hyperouranios topos);Phaedrus 247c ff. and in the Republic, the sensible world is contrasted with the intelligible realm (noēton topon) in the famous Allegory of the Cave.
It would be a mistake to take Plato's imagery as positing the intelligible world as a literal physical space apart from this one."No sensible man would insist that these things are as I have described them..." (Phd. 114d)."There is no Platonic 'elsewhere', similar to the Christian 'elsewhere'." (Iris Murdoch, "Metaphysics as a Guide to Morals" (London, Chatto & Windus 1992) 399). Plato emphasizes that the Forms are not beings that extend in space (or time), but rather subsist apart from any physical space whatsoever. Thus we read in the Symposium of the Form of Beauty: "It is not anywhere in another thing, as in an animal, or in earth, or in heaven, or in anything else, but itself by itself with itself" (211b). And in the Timaeus, Plato writes: "Since these things are so, we must agree that which keeps its own form unchangingly, which has not been brought into being and is not destroyed, which neither receives into itself anything else from anywhere else, nor itself enters into anything anywhere, is one thing." (52a; emphasis added.)
Ambiguities of the theory What are Forms? Plato's conception of Forms actually differs from dialogue to dialogue, and in certain respects it is never fully explained, so many aspects of the theory are open to interpretation. Forms are first introduced in the Phaedo, but in that dialogue the concept is taken as something with which the participants are already familiar, and the theory itself is not developed. Similarly, in the Republic, Plato relies on the concept of Forms as the basis of many of his arguments, but feels no need to argue at length for the validity of the theory itself. Commentators have been left with the task of explaining what Forms are and how physical objects participate in them, and there has been no shortage of disagreement.
Some scholars advance the view that Forms are paradigms, perfect examples on which the imperfect world is modeled; others place emphasis upon the Forms as universals, so that the Form of Beauty, for example, is that quality that all beautiful things share. Yet others interpret Forms as "stuffs", the conglomeration of all instances of a quality in the visible world; under this interpretation, we could say that there is a little beauty in one person, a little beauty in another, and so on—thence, all the beauty in the world put together is the Form of Beauty.
What things get Forms?