Hyponoetics - Glossary

Theories and Definitions of Thinking

The Encyclopedia of Philosophy, Volume VIII

Thinking is an essentially human activity occurring in two basic forms. We may think in order to attain knowledge of what is, must, or may be the case; we also may think with a view to making up our mind about what we will or will not do. Following Aristotle, these two forms of thought may be called, respectively, contemplation and deliberation.
Both forms may e carried on well or badly, successfully or unsuccessfully, intelligently or stupidly. When contemplation is successful, it terminates in a conclusion; successful deliberation terminates in a decision or resolution.
The form of reasoning involved in contemplation may be called theoretical, and the form involved in deliberation may be called practical. Obviously, our day-by-day reasoning in ordinary life is an untidy mixture of both these basic forms.

Less generally, thinking is commonly understood as a largely covert activity, something done mainly in foro interno . This activity is also conceived of as intentional in Franz Brentano's sense of "being directed towards an object". This object (or subject) of our thinking may be either abstract or concrete. In thinking about these various objects, we are also necessarily thinking something about them. We think of them as having various features, as doing something or other, or as being related in this or that way to other things of various sorts. Our specific thoughts have contents as well as objects.
Another distinctive feature of particular thoughts is that the language used to describe them is nonextensional in a rich sense that is commonly called intentional.

Thoughts involved in both contemplation and deliberation have the following basic features:

  1. they are characteristically, but perhaps not necessarily, carried on in foro interno .
  2. they are directed toward an object or a number of objects, and they either attribute something to, or deny something about, this object or objects.
  3. the language used to describe them is nonextensional
  4. thoughts are often conceived in relation to and are felicitously expressible by, specific verbal forms, that is, they are often essentially linguistic or conceptual.
  5. particular thoughts have some kind of logical form; they may be categorical, hypothetical, disjunctive, universal, particular and the like.

Traditional theories

According to the Platonist, thinking is either a dialogue in the soul involving mental words that refer to Forms and , possibly, to individuals or a spiritual activity of inspecting or recollecting Forms and discerning their natures and interrelations.

According to Aristotelianism, thinking is an act of the intellect in which a thing's essence, or intelligible form, actually qualifies the intellect; to think about humanity is for one's intellect to be informed by - literally, to share - the essence humanity.

For conceptualists (rationalists, Kant) thinking is an activity of bringing concepts or ideas before the mind, these being either innate and applicable to the world in virtue of God's grace (Leibniz, Descartes) or else formed by abstraction from sense experiences and thus actually sharing the abstract features of those experiences (Locke).

For imagists (Berkeley, Hume) thinking is basically a sequence of episodes involving Content/images; these Content/images are tied to certain "habits", which are the inveterate tendencies of the mind to move from one image to another. To think about triangularity is to imagine some particular triangle while disposed to pass on to other Content/images "of the same sort".

According to the psychological nominalist (Hobbes) thinking is literally a dialogue in the soul (or better in the head) involving the use of verbal Content/images, or mental words, which denote things or classes of things. A complete thought is a mental utterance of a sentence.

According to behaviorism, thinking is either thoughtful overt speech or a changing series of dispositions to behave intelligently that the agent can at any time avow.

The analogy theory: Silent thought need not be inner speech, but it may still be an activity that is at least formally analogous to speech. In what sense "formally analogous"? In the sense in which chess played with pennies and nickels is formally analogous to chess played with standard pieces.
While the thought p is empirically different from the act of saying that p, it may still be regarded as formally the same: both are activities that conform to the same principles and have many of the same implications (= formal identity among empirically different activities).

The Oxford Companion to Philosophy

Thinking. In its diverse forms--as reasoning, believing, reflecting, calculating, deliberating.

Thinking appears to enjoy an intimate connection with speech, but just what that connection might be is difficult to establish. It is seldom, as Plato would have it, a matter of an inward dialogue carried on by the mind with itself. Not only is wordless thought possible, as when we think how a room would look with the furniture rearranged; it does not even require attention to the matter in question for us to have thought that something was so, as when, tripping on a stair, we say we thought there was one fewer stair than there in fact was.

Is thinking that p a matter of being disposed to say that p? This is tempting through making reliance on the spoken word basic, but it does not get us far as it stands. First, while thinking that p we need have no inclination whatsoever to say that p; at best, the disposition must be restricted by an appropriate condition, as 'if asked to give our opinion'. Even then there is a supposition that we are speaking truthfully, and this would seem to be a matter of saying what we really think. A more satisfactory characterization might run: to think that p is to be in a state of mind expressible by saying that p with an intention to speak the truth. The latter condition is not 'intending to speak truthfully', which would again reintroduce thinking, but 'intending to say something that is in fact true'.

This characterization allows for a suitably loose connection between thought and speech in several respects: those who cannot in fact speak are not being denied the capacity to think, and indeed it is possible that someone should suggest a form of words which better expresses another's thought than the words originally used. It is also allowed that there should be a range of quite different propositions to which one might assent as expressing one's thought. You ask whether I thought the window was dirty. Yes indeed, I reply, but I could also have agreed if you had asked whether I thought there was a smudge on the window-pane, this being equally adequate to conveying how things struck me at the time. It is not as if the formulation ventured has to match unspoken words. I did not think in words. On the other hand, the characterization is also congenial to the idea that there are limits to the range of thoughts possible without language. Lacking the relevant vocabulary, a person could hardly be in a state of mind expressible by saying, with the relevant intention, that Sofia is the capital of Bulgaria.

Can animals think? We might say of a monkey which takes refuge from a snake by going up a tree that it knows that it is safe there. We might say this, because the monkey no longer behaves as if in imminent danger, but observes the snake in a detached fashion. However, while we may be prepared to say that it knows, we may be less happy to say that the monkey thinks that it is safe. That threatens to demand more of the monkey's mental capacities than we are wining to concede. On the other hand, we need a description for the case where there would be knowledge that p but for the fact that p is false, and while 'thinks that p' has the disadvantage of suggesting a mastery of concepts, an inner mental response, which it would be fanciful to attribute to the animal, so long as 'knows that p' can be affirmed solely on the strength of observed behaviour, the same status can be extended to the ascription of thought.

A.R. Lacey: A Dictionary of Philosophy

In the 17th century `thinking' was often used to cover mental phenomena in general, including feeling, with the result that Descartes and others could distinguish between substances according as they had extension or thinking as their main attributes. This usage is no longer current.

a) can take the forms of believing, imagining, pondering, calculating, deliberating, ruminating, assuming, evaluating;
b) something occurring at a given time or a state we can be in;
c) it can concern theoretical or practical matters.

Thinking is not a separate activity. It is therefore sometimes called polymorphous. This suggests an `adverbial' view of thinking, whereby there is no activity (or set of activities) to be called thinking but activities in general can be carried out thoughtfully or thoughtlessly, intelligently or unintelligently etc. This shows that intelligence or thoughtfulness can be manifested in the fact that something is done, as well as in the manner in which it is done.

A recently popular theory is that we have here simply physical events in the brain seen from a certain point of view (identity theory of mind).

Problem of the role of mental images, language and behavior.

Two questions:
a) How is thinking related to time? What is the structure of a thought, if it has one, related to that of a sentence expressing it?
b) How far can thoughts be described?

The question of the structure of a thought raises the question of how thinking a whole thought or proposition is related to thinking of an object (which the thought was about). Another important question about thinking concerns the things we think about. If I think about Caesar, does this constitute a relation between me and him?
With the idea that thought requires a representative, compare the representation theory of perception.

A further question we can ask is: WHAT IS IT THAT THINKS? Must a thought belong to a continuing thinker? When Descartes said `I think, therefore I am', what sort of an `I' did he prove the existence of?

Antony Flew: A Dictionary of Philosophy

The mental activity of

  1. theoretical contemplation directed towards some object with a view to reaching a propositional conclusion.
  2. practical deliberation directed towards some object with a view to reaching a decision to act.

Historically, there has been a wide variety of theories about what occurs in the process of thinking. For Descartes and Locke, the process involves bringing concepts or ideas before the mind; for Berkeley and Hume, the process constitutes a sequential series of ideas or images in the mind; for Hobbes, in an early version of a favoured modern view, the process is an activity that employs verbal images in a form of inner speech.
However, against this tendency to regard thinking as an essentially inner and conscious activity, Ryle and the behaviourists have argued that some states that may be described as thoughtful, contemplative, or deliberative are no more than dispositions to behave intelligently, dispositions which the agent may or may not articulate in words.

In contemporary philosophy, there are three main areas of concern with respect to the concept of thinking:

  1. the conceptual and linguistically based nature of thought (the relation of thinking to the way in which objects are conceived and enter into the language);
  2. the intentionality of thought (the way in which thought is necessarily directed towards an object);
  3. the intensionality, or non-extensionality, of thought (the implications of the fact that a thought t about an object o implies nothing in respect either of the existence of o or the truth or falsity of t).

Stephen Priest: What is Thinking?

The variety of activities called 'thinking' is extremely large but includes at least: reflecting, anticipating, deciding, imagining, remembering, wondering, pondering, intending, believing' , disbelieving, meditating, understanding, inferring, predicting and introspecting.

Thinking may take place in language, in an ordinary language such as English, or in an artificial language such as a logical notation. Some thinking also takes place in neither of those media but in mental images - pictures in the mind's eye.

'Thought' is ambiguous between 'what is thought' and 'the thinking of what is thought'. Thoughts may be true or false in the sense that what is thought may be true or false; so, if a person thinks that p, and p is true, then the thought that p is true; and if a person thinks that p, and p is false, then the thought that p is false. Also, there may obtain logical relations between thoughts because, for example, one thought may follow logically from another and contradict yet another.

All thinking has some subject matter. It does not make sense to say there is thinking that is not about anything. If there is thinking, there is something that is thought, some content, even if the thought is not truth-valued but, say, interrogative or subjunctive.

Thinking may be conscious or unconscious. If thinking is unconscious, then the mind thinking either does not know that it is thinking or, if it does know that, then it does not know what it is thinking. If thinking is conscious, then the thinking mind knows both that it is thinking and what it is thinking. Also, thinking may or may not have a phenomenology. Thinking has a phenomenology if and only if that thinking includes events which are experiences.

Thinking is a completely mental activity. I mean by this that no mental event is identical with any physical event and no mental event has any (intrinsic) physical properties. It logically follows from this that materialism is false because that is the conjunction of 'putatively mental events are physical' with 'only physical events exist'. I hold it to be self-contradictory to affirm that any mental event is a physical event, because mental and physical events are truly characterized by mutually exclusive predicates, for example, every physical event has size and no mental event has size; and it logically follows from those two premisses alone that no mental event is a physical event. It logically follows from that in turn that the first conjunct of materialism is false, because that is the claim that mental events are physical. It also follows that it is false that only physical events exist from the premisses that there exist mental events and that no mental event is identical with any physical event. It logically follows that the second conjunct of materialism is also false.

Materialism is a self-contradictory theory of the mind because it includes the claim that the mental is physical; but being mental partly consists in having no physical properties and being physical partly consists in having no mental properties. Being self-contradictory is a logically sufficient condition for being false, so it follows that materialism is false.

The relation between thinking and the brain is this: thinking is the mental activity of the brain. Crucially, there is no interface problem between things and their activities. There is no ontological or metaphysical problem about what the relation is between something and what it does. It is what I am calling the 'interface problem' that has proved most intractable in solving the mind-body problem: stating the nature of the interface between a mental event and a physical event. Materialists incoherently maintain that mental events are physical. Idealists incoherently maintain that physical events are mental. Dualists correctly maintain that no mental event is physical and that no physical event is mental but falsely believe in the interface problem.

To believe in the interface problem is to be in the grip of a metaphysical illusion, a powerful one which governs our self-conception. To help dispel the illusion, I provide a number of analogies. They are designed to show there is no ontological problem about something and its activities, or about a thing and what it does.

A light-bulb increases and diminishes in brightness, but there is no 'light-bulb-brightness' problem. Note that, were we to break the bulb or cut off the electrical supply, or if the filament were to wear out, the emission of light would cease. In the Lewis Carroll story Alice in Wonderland the speculative metaphysical possibility is imaginatively entertained of a 'grin without a cat'. Clearly, however, in empirical reality there may exist a cat without a grin but not a grin without a cat (or something that grins). This is because grinning is something the cat does. A chameleon is a lizard that can change its colour. Suppose the chameleon changes from blue to red. There is not thereby created a 'chameleon-colour-change problem', not just because secondary qualities logically depend upon primary qualities but also because changes logically depend upon things that change. If a bus is moving down the street, there is no 'bus-motion problem'. It is not as though the motion of the bus could exist as a ghostly see-through residue, were the bus to be dismantled. This is not just because primary qualities logically depend upon the physical objects they are properties of but also because moving is something the bus does and doings are impossible without the things that do them.

Nothing hinges, in any of these cases, on whether the things done are physical or mental or neither. It is because things done logically depend on things that do them that there is no interface problem.

In a similar way there need no longer be a mind-body problem. We, logically, could never be in a position to inspect the 'interface' between thinking and the brain. We could never, so to speak, peel thinking off the brain and discover metaphysical cement, cement that is not quite mental and not quite physical. To believe in the interface problem is to confuse an empirical possibility with a logical impossibility.

I call this solution to the mind-body problem 'Empiricism' even though, as a general thesis about thinking, it is analytic: 'thinking is the mental activity of minds'. As a particular truth about human beings and higher animals, it is empirical and contingent: 'thinking is the mental activity of the brain'. It is an important tenet of this empiricist theory of the mind that little sense may be attached to the metaphysical notion of a 'relation' between a thing and its activities. Something's activities are just what it does, whatever it is and whatever it does. All the facts about a thing's relation to what it does are empirical facts; none of them is metaphysical.

Notably there are no causal relations between things and their activities other than those to be mentioned in explaining how or why they engage in those activities. If we persist in thinking of thinking as a thing or substance, we will continue to ask about causal connections between thinking and the brain, instead of correctly regarding thinking as the mental activity of the brain. It is an empirical question, which parts of the brain are required for which kinds of thinking. There is no non-empirical causal question about thinking and the brain. It is an empirical truth that the brain is necessary for thinking in humans and higher animals, and it is an empirical truth that thinking is an activity, or something that is done. The empiricist theory of the mind is the identification of the brain with that which engages in the activity of thinking. This identification is itself empirical.
(THEORIES OF THE MIND, PENGUIN 1991, p. 213-216)

Hoffmeister: Wörterbuch der Philosophischen Begriffe

Denken - gr. noein , lat. cogitare

Im weitesten Sinn jedes aktive seelische Verhalten des Menschen im Unterschied zum Empfinden, Hingegebensein an Eindrücke, Waltenlassen von Bildern usw.

allgem. Sprachgebrauch: Erinnerung, anschauliches Vorstellen, Vermuten, Glauben, Hoffen, willentliches Gerichtetsein auf etwas, Vorhaben, Beabsichtigen etc.
Das Zusammenwirken, die Gesamtheit dieser einzelnen seelischen Verhaltungsweisen = das Denken des Individuums (gemeint ist seine Gesinnung, sein Charakter).
Denken = der entscheidende Wesenzug des Menschen (s. Aristoteles).

im philosophischen Sinn: Denken = diejenige von allem Anschauen und Vorstellen, Meinen und Nachdenken unterschiedene, selbständige und selbstgesetzliche Tätigkeit des Geistes, die auf das eigentlich Seiende, das Wesen der Sache, das wahrhaft Wirkliche geht. Das, was diese Tätigkeit hervorbringt, sind Selbstbestimmungen des Denkens = Gedanken.
Das philosophische Denken hat die überlieferten Ergebnisse je neu zu durchdenken.
--> Verbundenheit des Denkens mit der Sprache (Wort und Bedeutung).

im logisch-formalen Sinn: Denken = das fehlerfreie Arbeiten des Verstandes. Es bestimmt, vergleicht, unterscheidet, zerlegt die Begriffe, hebt das Gemeinsame an ihnen heraus, um ihre Beziehungen zueinander zu erkennen, führt neue, passendere Begriffe ein, verbindet sie zu Urteilen und Schlüssen miteinander und untersucht diese wieder auf ihre Gesetzmässigkeit usw. Während das philosophische Denken auf Wahrheit geht, strebt das logisch-formale nach Richtigkeit, es unterwirft sich den in der formalen Logik erarbeiteten Gesetzen und Regeln.

zur Entwicklung/Geschichte: Das philosophische Denken wurde zuerst von Parmenides (ca 500 B.C.) von dem bild- und sinnengebundenen, nur Meinung (doxa) erzeugenden Denken geschieden. Ebenso trennte Plato Denken (noesis) und Meinung. Er unterschied näher das reine Denken (nous), das auf die Urbilder geht; das auf Anschauung angewiesene, Zahlen und Raumgebilde erkennende Denken (dianoia); die Wahrnehmung (aisthesis), die die körperlichen Dinge, die Abbilder der Ideen, zum Gegenstand hat, und die nur mit den Spiegelbildern dieser Dinge beschäftigte eikasia. Das Denken ist für Plato ein Gespräch der Seele mit sich selbst (Soph. 263 E ff.).
Entsprechend der Zweiheit von Möglichkeit und Wirklichkeit, Stoff (gr. hyle, lat. materia) und Form (gr. morphe, lat. causa formalis) unterschied Aristoteles ein leidendes, passives, stoffgebundenes Denken (nous pathetikos) und ein tätiges, von nichts anderem bestimmtes, nur sich selbst bestimmendes, freies Denken (nous poietikos)(De An. III 5, 430 a). Der metaphysische Begriff eines "Denkens des Denkens" (noesis noeseos), von Aristoteles auch Theorie genannt.
Neuzeitliche Philosophie: Denken = vorwiegend subjektive Tätigkeit im Gegensatz zum objektiven Sein und Geschehen.

Hobbes: Denken = Rechnen, ein Addieren und Subtrahieren von Begriffen, die selbst nur Zeichen der Dinge sind.
Descartes: Denken = Bewusstsein im Gegensatz zum Körperlichen (Cogito ergo sum).
Locke (tabula rasa) und Hume: aller Stoff des Denkens wird durch die sinnliche Wahrnehmung gegeben. Denken hat nur die Aufgabe, diesen Stoff zu ordnen.
Leibniz: jede seelische Tätigkeit ist ein deutlicheres oder verworreneres Denken. Denken hat eine von der Sinneswahrnehmung unabhängige Eigengesetzlichkeit (Monade).
Aufklärung: Denken = höheres seelisches Vermögen neben anderen.
Kant: unterschied das Denken einerseits von der Anschauung, anderseits vom Erkennen. (s. KrV, B 146/165).
Hegel: Denken denkt sich selbst, indem es das Andere, den Gegenstand, denkt; es schliesst sich in ihm mit sich selbst zusammen (Dialektik).
19. Jh.: Denken wurde vielfach materialistisch und mechanistisch erklärt.
20. Jh.: Eigengesetzlichkeit des Denkens (Denkpsychologie).

Denkform: das Formale an den Gedanken und Gedankenverbindungen im Unterschied zu ihrem Inhalt.
Schleichermacher: Denkstoff und Denken
Reinhold: Denkformen = formale Logik
Hegel: Denkformen = Kantsche Kategorien (Kant: Kategorien = Gedankenformen).

Denkgesetze: vier Grundsätze des richtigen Denkens in der Logik:
1. Satz der Identität
2. Satz vom Widerspruch
3. Satz vom ausgeschlossenen Dritten
4. Satz vom zureichendem Grund

Denkpsychologie: von O. Külpe und seinen Schülern, der sog. Würzburger Schule, gebildeter Ausdruck zur Bezeichnung der von ihnen betriebenen experimentellen Erforschung der Denkvorgänge, von denen sie zeigten, dass sie nicht auf Assoziationen zurückgeführt werden können (vgl. Assoziationspsychologie). Hauptergebnis: Anerkennung "unanschaulicher" Bewusstseinsinhalte.

1. scholastische
2. experimentierene
3. dialektische
Alle Denktechniken sind nur ein Formales, das Nachahmbare, Reproduzierbare. Was im einzelnen Fall der Inhalt, der neue Inhalt wird, was überall das Schöpferische ist, das kommt nie durch die Technik als solche, sondern in allen Fällen durch Intuition.

Gedanke: bei Ch. Wolff für lat. perceptio und cogitatio .
1. der Vorgang des Denkens (Denkakt)
2. der erlebte Denkinhalt, das Erzeugnis oder Ergebnis des Denkens
3. der logische Wert, der ideale Gegenstand, der dadurch definiert wird, dass jede Aussage als Name eines Gedankens behandelt wird.
Versteht man unter Denken die Erfassung und Herstellung von Bedeutungen, Beziehungen und Sinneszusammenhängen, so ist hier Gedanke nicht gleichbedeutend mit Denkakt, auch nicht mit dem Erlebnis des Denkinhalts, sondern mit der Geltung, dem Sein der subjektunab-hängigen zeitunabhängigen Bedeutungen, Beziehungs- und Sinnzusammenhänge.
Im dt. Idealismus wird der Gedanke zwar betrachtet als von der Seele erzeugt, aber der erzeugte Gedanke gilt als eine "unabhängige, für sich fortwirkende Macht" (Schelling, W. VII, 347).

Gedankending: für lat. ens rationis , das bloss Gedachte, Vorgestellte, nicht in Raum und Zeit Wirkliche.

Arnold/Eysenck/Meili: Lexikon der Psychologie

1. Das Denken wird operational definiert als Herstellen von Ordnungen der angetroffenen Welt. Dieses Ordnen vollzieht sich an Gegenständen ebenso wie an den Repräsentationen der Gegenstandswelt. Das Denken ist auch das Ordnen von Beziehungen zwischen Gegenständen ebenso wie das Ordnen von Beziehungen zwischen Repräsentationen von Gegenständen.
Das ordnende Umgehen mit bildhaften und vorstellungsnahen Repräsentationen heisst anschauliches Denken .
Erfolgt die Ordnung der angetroffenen Wirklichkeit nach gefühlsmässigen und motivationalen Zuständen, die willkürlich die mit diesen Innenzuständen zufällig zusammentreffenen Personen, Sachen oder Gedanken verknüpft, liegt autistisches Denken vor.
Wenn Wunscherfüllungstendenzen die Denkergebnisse determinieren, sind primäre Denkprozesse, wenn dagegen rationale Ordnungstechniken das Denkresultat bestimmen, sind sekundäre Denkprozesse definiert (S. Freud).
Magisches Denken ordnet die Beziehungen zwischen Bild, Zeichen oder Symbol zum Objekt so als seien Gegenstände, Tiere oder Pflanzen ebenso wie ihre Repräsentationen handlungsfähig wie Menschen.
Werden nicht mehr vorstellungsfähige, unbildliche Repräsentationen, Gedanken und deren Beziehungen geordnet, liegt unanschauliches, abstraktes oder begriffliches Denken vor.

Konzepte sind verbale Vermittler zwischen wahrgenommenem Material (Reiz) und Ordnungsversuch (Reaktion) an diesem Material.

2. Erkenntnistheorie des dialektischen Materialismus: Entwicklung des Denkens im Prozess der praktischen Tätigkeit und des menschlichen Verkehrs. Die Produktion der Ideen, Vorstellungen, des Bewusstseins ist unmittelbar verflochten in die materielle Tätigkeit und den materiellen Verkehr der Menschen, Sprache des wirklichen Lebens. (Marx & Engels).
--> ontogenetische Entwicklung des Denkens

Denken und Sprache: Sprache ist nicht nur Mittel zum Ausdruck der Gedanken, sondern auch Grundelement oder Mechanismus des Denkens, mit dessen Hilfe von den unmittelbaren gegenständlichen Eindrücken und Handlungen abstrahiert wird und diese durch Denkbilder und Schemen in Verbindung mit äusseren oder inneren Sprache ersetzt werden.

Michael Inwood: A Hegel Dictionary

Thinking and Thought
'to think' in German is denken. 'Thinking' or '(the activity of) thought' is conveyed by the nominal infinitive, das Denken. Gedanke is usually not 'thought' as an activity, but '(a) thought' as the product or content of thinking. A Gedanke may be either a psychological entity ('His thoughts are confused', 'The thought of his arrival excited me') or an ideal, logical entity ('It is a comforting thought that the actual is rational'). The past participle of denken is gedacht. Hence Hegel associates it with the cognate Gedächtnis (memory, especially of words). Denken enters several compounds: especially important for Hegel is nachdenken (literally 'to after-think', hence 'to reflect') and das Nachdenken ('after-thinking, reflection'). But it is distinct from reflektieren and Reflexion (reflection), in that it has the favourable connotation of 'thinking over, about' what one has first encountered by, e.g., perception or feeling, and of producing thoughts about it (Enc. I (section)2).

In philosophy, as in everyday speech, 'thinking' can cover a wide range of mental activity. Leibniz and his followers regarded all psychical activity as thinking, differing only in its degree of clarity and distinctness. But Parmenides, Plato, etc., sharply distinguished thinking (to noein or noesis) from other faculties or activities, especially opinion (doxa) and perception. Against the Leibnizians, Kant distinguished thought sharply from intuition (Anschauung), and argued that cognition requires both thinking and intuition of an object. Thus while we can think about things in themselves, we cannot know about them since they supply no intuitions for our concepts. Kant (like Krug) held that one can think whatever one likes, as long as one does not contradict oneself. The law of contradiction thus has a special status among the Denkgesetze ('laws of thought'): a contradictory thought is no thought at all. Hegel rejects this doctrine, and the laws of thought in general, since he holds that thought, like reason, can neither accept from without, nor assign to itself, limits to its activity which it cannot surmount or think beyond. The discovery and overcoming of contradictions in our thinking plays an essential part in the advance of our thought.

When concepts or categories are not filled out with intuitions, they are, on Kant's view, merely Gedankenformen ('forms of thought(s)'). But a more common expression among his successors (e.g. Schleiermacher, Reinhold) is Denkform ('thought-form, form of thinking'), in contrast to Denkstoff ('material of thought, thinking'). Thought-forms are often equated with the forms of formal logic: e.g. the thought-form 'All S is P' becomes, by the addition of appropriate thought-material, the thought 'All men are mortal'. Hegel equates them with the subject-matter of logic, which includes both Kant's categories and the forms of formal logic: e.g. the thought-form of causality is involved in the concrete thought of a stone's breaking glass. Often he uses the word Denkbestimmung ( thought-determination ), and occasionally Gedankenbestimmung, as a near-synonym, but with the additional suggestions of the word Bestimmung. He often equates a thought-form or -determination with a thought, since (1) a thought-form is not, on his view, simply the form of a thought, but can also be the content of a thought, and (2) a concrete thought, of a horse or of a stone's breaking glass, is a conception ( Vorstellung), not strictly a thought.

Hegel sometimes equates a thought or thought-form with a concept. More often he distinguishes them, since the concept properly belongs only to the last phase of the Logic. But, like 'concept', 'thought' and 'thinking' are involved in a set of contrasts which Hegel attempts to sublate. They contrast with (1) the I* that thinks or 'has' thoughts; (2) other psychical activities of the I such as perceiving, imagining, etc.; and (3) with the object which I think about:

1. From Plato and Aristotle down to Kant, philosophers have associated the I and its identity with thought, rather than with, e.g., perception, desire or action, Hegel too insists that the I does not 'have' thoughts or thought-forms, but is identical with, or constituted by, them (Enc. I (section)20, 24A.I). Apart from the considerations under (2) below, he has two arguments for this. (a) To be an I is to be aware of oneself as an I, and awareness of oneself as an I involves thought, since the I is accessible only by way of pure thinking: the I as such provides no sensory material for perception or conception. (b) I cannot coherently distance myself from my thought(form)s, supposing that they are a tool that I uses (like a hammer) or that I might have lacked them (like a desire), since my thinking in these ways of my thoughts and of my relation to them involves the very thoughts from which I attempt to distance myself.

2. Hegel accepts Aristotle's doctrine that what distinguishes man from all other creatures is the ability to think, and infers (invalidly) that 'everything human is human because, and only because, it is produced by thinking' (Enc. I (section)2). Thus thinking is not simply one activity alongside others that we engage in. First, my other activities involve thought. My perceiving a horse as a horse, my conception of a horse, my feeling of the presence of God, etc., involve the thought(-form)s of, e.g., a thing, life, or the absolute. No animal, Hegel argues, has a morality or a religion, and this is because, even if morality or religion appear in the form of; e.g., feeling, they essentially involve thought. My feelings, etc., are not imbued with thought from birth, but my development into a full human being and my ability to claim my feelings, etc. (and my body) as my own requires their infusion with thought. This, Hegel believes, is at odds with Kant's doctrine that morality essentially involves a conflict between reason and our inclinations.

Second, my other activities, my perceiving, desiring, etc., are objects of my thinking in a way in which my thinking is not, conversely, an object of them. I can think that I am perceiving, that perception has individuals for its objects, etc., while I cannot perceive that I am thinking or that thinking is of universals. This exemplifies a general principle: Thinking is of, or 'overreaches' (übergreift), what is other than thought. Thinking of this type, especially the extraction of the pure thoughts implicit in feelings, etc. constitutes philosophical thinking, in contrast to the thinking involved in everyday activities.

3. Thinking does not simply contrast with its objects. First, the principle that thought overreaches what is other than thought applies here too. If a thing is individual (in contrast to the universality of thoughts) or even wholly alien to thought or unthinkable, it is nevertheless by thinking that I know this, and 'individual', 'alien to thought', and 'unthinkable' express thoughts, not, e.g., perceptions.

Second, the essence of things is discerned by thinking, not by perceiving, and constituted by thoughts, not by their external perceptible features that we first encounter. This is so both at the level of the natural sciences (e.g. electricity, discovered by Nachdenken, is the essence of lightning) and at the level of philosophy (e.g. the concept is the essence of the I). Thus thoughts are as much objective as subjective.

So far Hegel's view of the relation of thought to its objects is similar to Kant's. For Kant too, the thoughts that we apply to intuitions constitute the essence of the resulting things. But Hegel differs from Kant in that he rejects the view that thoughts are imposed by us on intrinsically thought-free intuitions. Thoughts are embedded in things independently of our thinking about them. It is only our thought about the Great Bear that makes it a unity, but, e.g., a horse is a self-determining unity; it is not unified solely by our thought about it. (This seemingly innocuous doctrine plays a part in Hegel's idealism and his belief that the absolute is spirit.)

Hegel also differs from Kant in stressing that we can think not only about what is other than thought, but about thought itself. In particular we can (in logic) think about thought(-form)s in terms of thought(-form)s. Such pure thinking needs no external intuitions, and yet is, on Hegel's view, non-arbitrary and constitutes cognition. He associates such thinking with the noesis noeseos ('thinking of/about thinking') that Aristotle ascribes to God, and Plotinus to the 'true intellect (nous)'.

When Hegel says that thought or thinking is infinite, he means several things: (1) Thought(-form)s are not sharply distinct from, and bounded by, each other; they are knit together by reason and dialectic. (2) Thought(s) overreach what is other than thought. (3) Thought can think about itself. (4) Thought as a whole has no limits. Finite thoughts, by contrast, are segments of thought that are (a) treated as distinct from other thoughts; (b) treated as distinct from things; (c) incapable of, or not regarded as, applying to themselves; and/or (d) applicable to, or thoughts of, finite entities.

Howard Caygill: A Kant Dictionary

Thinking (Denken) is distinct from both knowing (Wissen) and cognition (Erkenntnis), although these distinctions are not observed in translation; nor are they uniformly observed by Kant. Thinking consists in 'uniting representations in a consciousness' and the latter is a description of judgement; 'thinking therefore is the same as judging' (Prolegomena SS22). As such it is an activity proper to the understanding, for 'through mere intuition nothing is thought' (Critique of Pure Reason A 253/B 309). The unification of representations accomplished in thinking is based on spontaneous, pure apperception of the 'I think', which is also entitled the 'transcendental unity of self-consciousness' which indicates 'the possibility of a priori knowledge arising from it' (CPR B 132). Although at one point Kant describes thinking as 'cognition by means of concepts' (CPR A 69/B 94), apparently suggesting that thinking is a form of cognition, he otherwise consistently distinguishes between them. In order to cognize an object 'I must be able to prove its possibility, either from its actuality as attested by experience, or a priori by means of reason' but 'I can think whatever I please, provided only that I do not contradict myself' (CPR B xxvi). Thus it is possible to think things-in-themselves, but not to know them, for as Kant 'reminds' his readers 'for thought the categories are not limited by the conditions of our sensible intuition, but have an unlimited field' (CPR B 166). It is, of course, also possible for thinking to be consistent with cognition, as in the case of synthetic a priori judgements where 'thinking is the act whereby given intuitions are related to an object' (CPR A 247/B 304). Such thinking must fulfil the conditions for the subsumption of intuitions under concepts, and its objects are accordingly restricted to those of a possible experience.