I. The Three Intuitions
IA. Eidetic Intuitions
Intuition is supposed to be a form of direct access. Yet, direct access to what? Does it access directly "intuitions" (abstract objects, akin to numbers or properties - see "Bestowed Existence")? Are intuitions the objects of the mental act of Intuition? Perhaps intuition is the mind's way of interacting directly with Platonic ideals or Phenomenological "essences"? By "directly" I mean without the intellectual mediation of a manipulated symbol system, and without the benefits of inference, observation, experience, or reason.
Kant thought that both (Euclidean) space and time are intuited. In other words, he thought that the senses interact with our (transcendental) intuitions to produce synthetic a-priori knowledge. The raw data obtained by our senses -our sensa or sensory experience - presuppose intuition. One could argue that intuition is independent of our senses. Thus, these intuitions (call them "eidetic intuitions") would not be the result of sensory data, or of calculation, or of the processing and manipulation of same. Kant's "Erscheiung" ("phenomenon", or "appearance" of an object to the senses) is actually a kind of sense-intuition later processed by the categories of substance and cause. As opposed to the phenomenon, the "nuomenon" (thing in itself) is not subject to these categories.
Descartes' "I (think therefore I) am" is an immediate and indubitable innate intuition from which his metaphysical system is derived. Descartes' work in this respect is reminiscent of Gnosticism in which the intuition of the mystery of the self leads to revelation.
Bergson described a kind of instinctual empathic intuition which penetrates objects and persons, identifies with them and, in this way, derives knowledge about the absolutes - "duration" (the essence of all living things) and "élan vital" (the creative life force). He wrote: "(Intuition is an) instinct that has become disinterested, self-conscious, capable of reflecting upon its object and of enlarging it indefinitely." Thus, to him, science (the use of symbols by our intelligence to describe reality) is the falsification of reality. Only art, based on intuition, unhindered by mediating thought, not warped by symbols - provides one with access to reality.
Spinoza's and Bergson's intuited knowledge of the world as an interconnected whole is also an "eidetic intuition".
Spinoza thought that intuitive knowledge is superior to both empirical (sense) knowledge and scientific (reasoning) knowledge. It unites the mind with the Infinite Being and reveals to it an orderly, holistic, Universe.
Friedrich Schleiermacher and Rudolf Otto discussed the religious experience of the "numinous" (God, or the spiritual power) as a kind of intuitive, pre-lingual, and immediate feeling.
Croce distinguished "concept" (representation or classification) from "intuition" (expression of the individuality of an objet d'art). Aesthetic interest is intuitive. Art, according to Croce and Collingwood, should be mainly concerned with expression (i.e., with intuition) as an end unto itself, unconcerned with other ends (e.g., expressing certain states of mind).
Eidetic intuitions are also similar to "paramartha satya" (the "ultimate truth") in the Madhyamika school of Buddhist thought. The ultimate truth cannot be expressed verbally and is beyond empirical (and illusory) phenomena. Eastern thought (e.g. Zen Buddhism) uses intuition (or experience) to study reality in a non-dualistic manner.
IB. Emergent Intuitions
A second type of intuition is the "emergent intuition". Subjectively, the intuiting person has the impression of a "shortcut" or even a "short circuiting" of his usually linear thought processes often based on trial and error. This type of intuition feels "magical", a quantum leap from premise to conclusion, the parsimonious selection of the useful and the workable from a myriad possibilities. Intuition, in other words, is rather like a dreamlike truncated thought process, the subjective equivalent of a wormhole in Cosmology. It is often preceded by periods of frustration, dead ends, failures, and blind alleys in one's work.
Artists - especially performing artists (like musicians) - often describe their interpretation of an artwork (e.g., a musical piece) in terms of this type of intuition. Many mathematicians and physicists (following a kind of Pythagorean tradition) use emergent intuitions in solving general nonlinear equations (by guessing the approximants) or partial differential equations.
Henri Poincaret insisted (in a presentation to the Psychological Society of Paris, 1901) that even simple mathematical operations require an "intuition of mathematical order" without which no creativity in mathematics is possible. He described how some of his creative work occurred to him out of the blue and without any preparation, the result of emergent intuitions. These intuitions had "the characteristics of brevity, suddenness and immediate certainty... Most striking at first is this appearance of sudden illumination, a manifest sign of long, unconscious prior work. The role of this unconscious work in mathematical invention appears to me incontestable, and traces of it would be found in other cases where it is less evident."
Subjectively, emergent intuitions are indistinguishable from insights. Yet insight is more "cognitive" and structured and concerned with objective learning and knowledge. It is a novel reaction or solution, based on already acquired responses and skills, to new stimuli and challenges. Still, a strong emotional (e.g., aesthetic) correlate usually exists in both insight and emergent intuition.
Intuition and insight are strong elements in creativity, the human response to an ever changing environment. They are shock inducers and destabilizers. Their aim is to move the organism from one established equilibrium to the next and thus better prepare it to cope with new possibilities, challenges, and experiences. Both insight and intuition are in the realm of the unconscious, the simple, and the mentally disordered. Hence the great importance of obtaining insights and integrating them in psychoanalysis - an equilibrium altering therapy.
IC. Ideal Intuitions
The third type of intuition is the "ideal intuition". These are thoughts and feelings that precede any intellectual analysis and underlie it. Moral ideals and rules may be such intuitions (see "Morality - a State of Mind?"). Mathematical and logical axioms and basic rules of inference ("necessary truths") may also turn out to be intuitions. These moral, mathematical, and logical self-evident conventions do not relate to the world. They are elements of the languages we use to describe the world (or of the codes that regulate our conduct in it). It follows that these a-priori languages and codes are nothing but the set of our embedded ideal intuitions.
As the Rationalists realized, ideal intuitions (a class of undeniable, self-evident truths and principles) can be accessed by our intellect. Rationalism is concerned with intuitions - though only with those intuitions available to reason and intellect. Sometimes, the boundary between intuition and deductive reasoning is blurred as they both yield the same results. Moreover, intuitions can be combined to yield metaphysical or philosophical systems. Descartes applied ideal intuitions (e.g., reason) to his eidetic intuitions to yield his metaphysics. Husserl, Twardowki, even Bolzano did the same in developing the philosophical school of Phenomenology.
The a-priori nature of intuitions of the first and the third kind led thinkers, such as Adolf Lasson, to associate it with Mysticism. He called it an "intellectual vision" which leads to the "essence of things". Earlier philosophers and theologians labeled the methodical application of intuitions - the "science of the ultimates". Of course, this misses the strong emotional content of mystical experiences.
Confucius talked about fulfilling and seeking one's "human nature" (or "ren") as "the Way". This nature is not the result of learning or deliberation. It is innate. It is intuitive and, in turn, produces additional, clear intuitions ("yong") as to right and wrong, productive and destructive, good and evil. The "operation of the natural law" requires that there be no rigid codex, but only constant change guided by the central and harmonious intuition of life.
II. Philosophers on Intuition - An Overview
But are intuitions really a-priori - or do they develop in response to a relatively stable reality and in interaction with it? Would we have had intuitions in a chaotic, capricious, and utterly unpredictable and disordered universe? Do intuitions emerge to counter-balance surprises?
Locke thought that intuition is a learned and cumulative response to sensation. The assumption of innate ideas is unnecessary. The mind is like a blank sheet of paper, filled gradually by experience - by the sum total of observations of external objects and of internal "reflections" (i.e., operations of the mind). Ideas (i.e., what the mind perceives in itself or in immediate objects) are triggered by the qualities of objects.
But, despite himself, Locke was also reduced to ideal (innate) intuitions. According to Locke, a colour, for instance, can be either an idea in the mind (i.e., ideal intuition) - or the quality of an object that causes this idea in the mind (i.e., that evokes the ideal intuition). Moreover, his "primary qualities" (qualities shared by all objects) come close to being eidetic intuitions.
Locke himself admits that there is no resemblance or correlation between the idea in the mind and the (secondary) qualities that provoked it. Berkeley demolished Locke's preposterous claim that there is such resemblance (or mapping) between PRIMARY qualities and the ideas that they provoke in the mind. It would seem therefore that Locke's "ideas in the mind" are in the mind irrespective and independent of the qualities that produce them. In other words, they are a-priori. Locke resorts to abstraction in order to repudiate it.
Locke himself talks about "intuitive knowledge". It is when the mind "perceives the agreement or disagreement of two ideas immediately by themselves, without the intervention of any other... the knowledge of our own being we have by intuition... the mind is presently filled with the clear light of it. It is on this intuition that depends all the certainty and evidence of all our knowledge... (Knowledge is the) perception of the connection of and agreement, or disagreement and repugnancy, of any of our ideas."
Knowledge is intuitive intellectual perception. Even when demonstrated (and few things, mainly ideas, can be intuited and demonstrated - relations within the physical realm cannot be grasped intuitively), each step in the demonstration is observed intuitionally. Locke's "sensitive knowledge" is also a form of intuition (known as "intuitive cognition" in the Middle Ages). It is the perceived certainty that there exist finite objects outside us. The knowledge of one's existence is an intuition as well. But both these intuitions are judgmental and rely on probabilities.
Hume denied the existence of innate ideas. According to him, all ideas are based either on sense impressions or on simpler ideas. But even Hume accepted that there are propositions known by the pure intellect (as opposed to propositions dependent on sensory input). These deal with the relations between ideas and they are (logically) necessarily true . Even though reason is used in order to prove them - they are independently true all the same because they merely reveal the meaning or information implicit in the definitions of their own terms. These propositions teach us nothing about the nature of things because they are, at bottom, self referential (equivalent to Kant's "analytic propositions").
According to Kant, our senses acquaint us with the particulars of things and thus provide us with intuitions. The faculty of understanding provided us with useful taxonomies of particulars ("concepts"). Yet, concepts without intuitions were as empty and futile as intuitions without concepts. Perceptions ("phenomena") are the composite of the sensations caused by the perceived objects and the mind's reactions to such sensations ("form"). These reactions are the product of intuition.
IID. The Absolute Idealists
Schelling suggested a featureless, undifferentiated, union of opposites as the Absolute Ideal. Intellectual intuition entails such a union of opposites (subject and object) and, thus, is immersed and assimilated by the Absolute and becomes as featureless and undifferentiated as the Absolute is.
Objective Idealists claimed that we can know ultimate (spiritual) reality by intuition (or thought) independent of the senses (the mystical argument). The mediation of words and symbol systems only distorts the "signal" and inhibits the effective application of one's intuition to the attainment of real, immutable, knowledge.
IIE. The Phenomenologists
The Phenomenological point of view is that every thing has an invariable and irreducible "essence" ("Eidos", as distinguished from contingent information about the thing). We can grasp this essence only intuitively ("Eidetic Reduction"). This process - of transcending the concrete and reaching for the essential - is independent of facts, concrete objects, or mental constructs. But it is not free from methodology ("free variation"), from factual knowledge, or from ideal intuitions. The Phenomenologist is forced to make the knowledge of facts his point of departure. He then applies a certain methodology (he varies the nature and specifications of the studied object to reveal its essence) which relies entirely on ideal intuitions (such as the rules of logic).
Phenomenology, in other words, is an Idealistic form of Rationalism. It applies reason to discover Platonic (Idealism) essences. Like Rationalism, it is not empirical (it is not based on sense data). Actually, it is anti-empirical - it "brackets" the concrete and the factual in its attempt to delve beyond appearances and into essences. It calls for the application of intuition (Anschauung) to discover essential insights (Wesenseinsichten).
"Phenomenon" in Phenomenology is that which is known by consciousness and in it. Phenomenologists regarded intuition as a "pure", direct, and primitive way of reducing clutter in reality. It is immediate and the basis of a higher level perception. A philosophical system built on intuition would, perforce, be non speculative. Hence, Phenomenology's emphasis on the study of consciousness (and intuition) rather than on the study of (deceiving) reality. It is through "Wesensschau" (the intuition of essences) that one reaches the invariant nature of things (by applying free variation techniques).
The Manifold of Sense