Being is the general concept encompassing objective and subjective
features of reality and existence. Anything that partakes in being is
also called a "being", though often this usage is limited to entities
that have subjectivity (as in the expression "human being"). The
notion of "being" has, inevitably, been elusive and controversial in
the history of philosophy, beginning in
Western philosophy with
attempts among the pre-Socratics to deploy it intelligibly.
As an example of efforts in recent times,
Martin Heidegger (who
himself drew on ancient Greek sources) adopted after German terms like
Dasein to articulate the topic. Several modern approaches build on
such continental European exemplars as Heidegger, and apply
metaphysical results to the understanding of human psychology and the
human condition generally (notably in the Existentialist tradition).
By contrast, in mainstream
Analytical philosophy the topic is more
confined to abstract investigation, in the work of such influential
theorists as W. V. O. Quine, to name one of many. One most fundamental
question that continues to exercise philosophers is put by William
James: "How comes the world to be here at all instead of the nonentity
which might be imagined in its place? ... from nothing to being
there is no logical bridge."
1 The substantial being
Being and the substance theorists
1.2 Aristotle's theory of act and potency
2 The transcendental being
2.1 Thomistic analogical predication of being
2.2 The transcendentals
Being in Islamic philosophy
Being in the Age of Reason
4.1 Empiricist doubts
4.2 Idealist systems
Being in continental philosophy and existentialism
6 See also
9 External links
The substantial being
Being and the substance theorists
The deficit of such a bridge was first encountered in history by the
Pre-Socratic philosophers during the process of evolving a
classification of all beings (noun). Aristotle, who wrote after the
Pre-Socratics, applies the term category (perhaps not originally) to
ten highest-level classes. They comprise one category of substance
(ousiae) existing independently (man, tree) and nine categories of
accidents, which can only exist in something else (time, place). In
Aristotle, substances are to be clarified by stating their definition:
a note expressing a larger class (the genus) followed by further notes
expressing specific differences (differentiae) within the class. The
substance so defined was a species. For example, the species, man, may
be defined as an animal (genus) that is rational (difference). As the
difference is potential within the genus; that is, an animal may or
may not be rational, the difference is not identical to, and may be
distinct from, the genus.
Applied to being, the system fails to arrive at a definition for the
simple reason that no difference can be found. The species, the genus,
and the difference are all equally being: a being is a being that is
being. The genus cannot be nothing because nothing is not a class of
everything. The trivial solution that being is being added to nothing
is only a tautology: being is being. There is no simpler intermediary
between being and non-being that explains and classifies being.
Being according to Parmenides: a sphere.
Pre-Socratic reaction to this deficit was varied. As substance
theorists they accepted a priori the hypothesis that appearances are
deceiving, that reality is to be reached through reasoning. Parmenides
reasoned that if everything is identical to being and being is a
category of the same thing then there can be neither differences
between things nor any change. To be different, or to change, would
amount to becoming or being non-being; that is, not existing.
Therefore, being is a homogeneous and non-differentiated sphere and
the appearance of beings is illusory. Heraclitus, on the other hand,
foreshadowed modern thought by denying existence.
Reality does not
exist, it flows, and beings are an illusion upon the flow.
Aristotle knew of this tradition when he began his Metaphysics, and
had already drawn his own conclusion, which he presented under the
guise of asking what being is:
"And indeed the question which was raised of old is raised now and
always, and is always the subject of doubt, viz., what being is, is
just the question, what is substance? For it is this that some assert
to be one, others more than one, and that some assert to be limited in
number, others unlimited. And so we also must consider chiefly and
primarily and almost exclusively what that is which is in this sense."
and reiterates in no uncertain terms: "Nothing, then, which is not
a species of a genus will have an essence – only species will have
it ....". Being, however, for Aristotle, is not a genus.
Aristotle's theory of act and potency
One might expect a solution to follow from such certain language but
none does. Instead
Aristotle launches into a rephrasing of the
problem, the Theory of Act and Potency. In the definition of man as a
Aristotle presumes that "two-legged" and "animal"
are parts of other beings, but as far as man is concerned, are only
potentially man. At the point where they are united into a single
being, man, the being, becomes actual, or real. Unity is the basis of
actuality: "... 'being' is being combined and one, and 'not being'
is being not combined but more than one." Actuality has taken the
place of existence, but
Aristotle is no longer seeking to know what
the actual is; he accepts it without question as something generated
from the potential. He has found a "half-being" or a "pre-being", the
potency, which is fully being as part of some other substance.
Substances, in Aristotle, unite what they actually are now with
everything they might become.
The transcendental being
Some of Thomas Aquinas' propositions were reputedly condemned by
Étienne Tempier, the local Bishop of Paris (not the Papal Magisterium
itself) in 1270 and 1277, but his dedication to the use of
philosophy to elucidate theology was so thorough that he was
Doctor of the Church
Doctor of the Church in 1568. Those who adopt it are
Thomistic analogical predication of being
In a single sentence, parallel to Aristotle's statement asserting that
being is substance, St. Thomas pushes away from the Aristotelian
Being is not a genus, since it is not predicated
univocally but only analogically." His term for analogy is Latin
analogia. In the categorical classification of all beings, all
substances are partly the same: man and chimpanzee are both animals
and the animal part in man is "the same" as the animal part in
chimpanzee. Most fundamentally all substances are matter, a theme
taken up by science, which postulated one or more matters, such as
earth, air, fire or water (Empedocles). In today's chemistry the
carbon, hydrogen, oxygen and nitrogen in a chimpanzee are identical to
the same elements in a man.
The original text reads, "Although equivocal predications must be
reduced to univocal, still in actions, the non-univocal agent must
precede the univocal agent. For the non-univocal agent is the
universal cause of the whole species, as for instance the sun is the
cause of the generation of all men; whereas the univocal agent is not
the universal efficient cause of the whole species (otherwise it would
be the cause of itself, since it is contained in the species), but is
a particular cause of this individual which it places under the
species by way of participation. Therefore the universal cause of the
whole species is not an univocal agent; and the universal cause comes
before the particular cause. But this universal agent, whilst it is
not univocal, nevertheless is not altogether equivocal, otherwise it
could not produce its own likeness, but rather it is to be called an
analogical agent, as all univocal predications are reduced to one
first non-univocal analogical predication, which is being."
If substance is the highest category and there is no substance, being,
then the unity perceived in all beings by virtue of their existing
must be viewed in another way. St. Thomas chose the analogy: all
beings are like, or analogous to, each other in existing. This
comparison is the basis of his Analogy of Being. The analogy is said
of being in many different ways, but the key to it is the real
distinction between existence and essence.
Existence is the principle
that gives reality to an essence not the same in any way as the
existence: "If things having essences are real, and it is not of their
essence to be, then the reality of these things must be found in some
principle other than (really distinct from) their essence."
Substance can be real or not. What makes an individual substance – a
man, a tree, a planet – real is a distinct act, a "to be", which
actuates its unity. An analogy of proportion is therefore
possible: "essence is related to existence as potency is related
Existences are not things; they do not themselves exist, they lend
themselves to essences, which do not intrinsically have them. They
have no nature; an existence receives its nature from the essence it
Existence is not being; it gives being – here a customary
phrase is used, existence is a principle (a source) of being, not a
previous source, but one which is continually in effect. The stage is
set for the concept of God as the cause of all existence, who, as the
Almighty, holds everything actual without reason or explanation as an
act purely of will.
Aristotle's classificatory scheme had included the five predicables,
or characteristics that might be predicated of a substance. One of
these was the property, an essential universal true of the species,
but not in the definition (in modern terms, some examples would be
grammatical language, a property of man, or a spectral pattern
characteristic of an element, both of which are defined in other
ways). Pointing out that predicables are predicated univocally of
substances; that is, they refer to "the same thing" found in each
instance, St. Thomas argued that whatever can be said about being is
not univocal, because all beings are unique, each actuated by a unique
existence. It is the analogous possession of an existence that allows
them to be identified as being; therefore, being is an analogous
Whatever can be predicated of all things is universal-like but not
universal, category-like but not a category. St. Thomas called them
(perhaps not originally) the transcendentia, "transcendentals",
because they "climb above" the categories, just as being climbs above
substance. Later academics also referred to them as "the properties of
being." The number is generally three or four.
Being in Islamic philosophy
The nature of "being" has also been debated and explored in Islamic
philosophy, notably by
Ibn Sina (Avicenna), Suhrawardi, and Mulla
A modern linguistic approach which notices that
Persian language has
exceptionally developed two kinds of "is"es, i.e. ast ("is", as a
copula) and hast (as an existential "is") examines the linguistic
properties of the two lexemes in the first place, then evaluates how
the statements made by other languages with regard to being can stand
the test of Persian frame of reference.
In this modern linguistic approach, it is noticed that the original
language of the source, e.g. Greek (like German or French or English),
has only one word for two concepts, ast and hast, or, like Arabic, has
no word at all for either word. It therefore exploits the Persian hast
(existential is) versus ast (predicative is or copula) to address both
Western and Islamic ontological arguments on being and existence.
This linguistic method shows the scope of confusion created by
languages which cannot differentiate between existential be and
copula. It manifests, for instance, that the main theme of Heidegger's
Being and Time is astī (is-ness) rather than hastī (existence).
When, in the beginning of his book, Heidegger claims that people
always talk about existence in their everyday language, without
knowing what it means, the example he resorts to is: "the sky is blue"
which in Persian can be ONLY translated with the use of the copula
ast, and says nothing about being or existence.
In the same manner, the linguistic method addresses the ontological
works written in Arabic. Since Arabic, like
Latin in Europe, had
become the official language of philosophical and scientific works in
the so-called Islamic World, the early Persian or Arab philosophers
had difficulty discussing being or existence, since the Arabic
language, like other Semitic languages, had no verb for either
predicative "be" (copula) or existential "be". So if you try to
translate the aforementioned Heidegger's example into Arabic it
appears as السماء زرقاء (viz. "The Sky-- blue") with no
linking "is" to be a sign of existential statement. To overcome the
problem, when translating the ancient Greek philosophy, certain words
were coined like ایس aysa (from Arabic لیس laysa 'not') for
'is'. Eventually the Arabic verb وجد wajada (to find) prevailed,
since it was thought that whatever is existent, is to be "found" in
the world. Hence existence or
Being was called وجود wujud (Cf.
Swedish finns [found]> there exist; also the
of exsistere 'standing out (there in the world)' > appear>
Now, with regard to the fact that Persian, as the mother tongue of
Avicenna and Sadrā, was in conflict with either Greek or Arabic
in this regard, these philosophers should have been warned implicitly
by their mother tongue not to confuse two kinds of linguistic beings
(viz. copula vs. existential). In fact when analyzed thoroughly,
copula, or Persian ast ('is') indicates an ever-moving chain of
relations with no fixed entity to hold onto (every entity, say A, will
be dissolved into "A is B" and so on, as soon as one tries to define
it). Therefore, the whole reality or what we see as existence ("found"
in our world) resembles an ever-changing world of astī (is-ness)
flowing in time and space. On the other hand, while Persian ast can be
considered as the 3rd person singular of the verb 'to be', there is no
verb but an arbitrary one supporting hast ('is' as an existential be=
exists) has neither future nor past tense and nor a negative form of
its own: hast is just a single untouchable lexeme. It needs no other
linguistic element to be complete (Hast. is a complete sentence
meaning "s/he it exists"). In fact, any manipulation of the arbitrary
verb, e.g. its conjugation, turns hast back into a copula.
Eventually from such linguistic analyses, it appears that while astī
(is-ness) would resemble the world of Heraclitus, hastī (existence)
would rather approaches a metaphysical concept resembling the
Parmenidas's interpretation of existence.
In this regard, Avicenna, who was a firm follower of Aristotle, could
not accept either Heraclitian is-ness (where only constant was
change), nor Parmenidean monist immoveable existence (the hastī
itself being constant). To solve the contradiction, it so appeared to
Philosophers of Islamic world that
Aristotle considered the core of
existence (i.e. its substance/essence) as a fixed constant, while its
facade (accident) was prone to change. To translate such a
philosophical image into Persian it is like having hastī (existence)
as a unique constant core covered by astī (is-ness) as a cloud of
ever-changing relationships. It is clear that the Persian language,
deconstructs such a composite as a sheer mirage, since it is not clear
how to link the interior core (existence) with the exterior shell
(is-ness). Furthermore, hast cannot be linked to anything but itself
(as it is self-referent).
The argument has a theological echos as well: assuming that God is the
Existence, beyond time and space, a question is raised by philosophers
of the Islamic world as how he, as a transcendental existence, may
ever create or contact a world of is-ness in space-time.
Avicenna who was more philosopher than theologian, followed
the same line of argumentation as that of his ancient master,
Aristotle, and tried to reconcile between ast and hast, by considering
the latter as higher order of existence than the former. It is like a
hierarchical order of existence. It was a philosophical Tower of Babel
that the restriction of his own mother tongue (Persian) would not
allow to be built, but he could maneuver in Arabic by giving the two
concepts the same name wujud, although with different attributes. So,
implicitly, astī (is-ness) appears as ممکن الوجود
"momken-al-wujud" (contingent being), and hastī (existence) as
واجب الوجود "wājeb-al-wujud" (necessary being).
On the other hand, centuries later, Sadrā, chose a more radical
route, by inclining towards the reality of astī (is-ness), as the
true mode of existence, and tried to get rid of the concept of hastī
(existence as fixed or immovable). Thus, in his philosophy, the
universal movement penetrates deep into the Aristotelian
substance/essence, in unison with changing accident. He called this
deep existential change حرکت جوهری harekat-e jowhari
(Substantial Movement). It is obvious that in such a changing
existence, the whole world has to go through instantaneous
annihilation and recreation incessantly, while as
predicted in his remarks on Nature, such a universal change or
substantial movement would eventually entail the shortening and
lengthening of time as well which has never been observed. This
logical objection, which was made on Aristotle's argumentation, could
not be answered in the ancient times or medieval age, but now it does
not sound contradictory to the real nature of
Time (as addressed in
relativity theory), so by a reverse argument, a philosopher may indeed
deduce that everything is changing (moving) even in the deepest core
Being in the Age of Reason
Although innovated in the late medieval period,
Thomism was dogmatized
in the Renaissance. From roughly 1277 to 1567, it dominated the
philosophic landscape. The rationalist philosophers, however, with a
new emphasis on
Reason as a tool of the intellect, brought the
classical and medieval traditions under new scrutiny, exercising a new
concept of doubt, with varying outcomes. Foremost among the new
doubters were the empiricists, the advocates of scientific method,
with its emphasis on experimentation and reliance on evidence gathered
from sensory experience. In parallel with the revolutions against
rising political absolutism based on established religion and the
replacement of faith by reasonable faith, new systems of metaphysics
were promulgated in the lecture halls by charismatic professors, such
as Immanuel Kant, and Hegel. The late 19th and 20th centuries featured
an emotional return to the concept of existence under the name of
existentialism. These philosophers were concerned mainly with ethics
and religion. The metaphysical side became the domain of the
phenomenalists. In parallel with these philosophies
under the protection of the Catholic Church; in particular, the Jesuit
Rationalism and empiricism have had many definitions, most concerned
with specific schools of philosophy or groups of philosophers in
particular countries, such as Germany. In general rationalism is the
predominant school of thought in the multi-national, cross-cultural
Age of reason, which began in the century straddling 1600 as a
conventional date, empiricism is the reliance on sensory data
gathered in experimentation by scientists of any country, who, in the
Reason were rationalists. An early professed empiricist, Thomas
Hobbes, known as an eccentric denizen of the court of Charles II of
England (an "old bear"), published in 1651 Leviathan, a political
treatise written during the English civil war, containing an early
manifesto in English of rationalism.
"The Latines called Accounts of mony Rationes ... and thence it seems
to proceed that they extended the word Ratio, to the faculty of
Reckoning in all other things....When a man reasoneth hee does nothing
else but conceive a summe totall ... For
Reason ... is nothing but
Reckoning ... of the consequences of generall names agreed upon, for
the marking and signifying of our thoughts ...."
In Hobbes reasoning is the right process of drawing conclusions from
definitions (the "names agreed upon"). He goes on to define error as
self-contradiction of definition ("an absurdity, or senselesse
Speech") or conclusions that do not follow the definitions on
which they are supposed to be based. Science, on the other hand, is
the outcome of "right reasoning," which is based on "natural sense and
imagination", a kind of sensitivity to nature, as "nature it selfe
Having chosen his ground carefully Hobbes launches an epistemological
attack on metaphysics. The academic philosophers had arrived at the
Matter and Form from consideration of certain natural
paradoxes subsumed under the general heading of the Unity Problem. For
example, a body appears to be one thing and yet it is distributed into
many parts. Which is it, one or many?
Aristotle had arrived at the
real distinction between matter and form, metaphysical components
whose interpenetration produces the paradox. The whole unity comes
from the substantial form and the distribution into parts from the
matter. Inhering in the parts giving them really distinct unities are
the accidental forms. The unity of the whole being is actuated by
another really distinct principle, the existence.
If nature cannot err, then there are no paradoxes in it; to Hobbes,
the paradox is a form of the absurd, which is inconsistency:
"Natural sense and imagination, are not subject to absurdity" and "For
error is but a deception ... But when we make a generall assertion,
unlesse it be a true one, the possibility of it is inconceivable. And
words whereby we conceive nothing but the sound, are those we call
Absurd ...." Among Hobbes examples are "round quadrangle", "immaterial
substance", "free subject." Of the scholastics he says:
"Yet they will have us beleeve, that by the Almighty power of God, one
body may be at one and the same time in many places [the problem of
the universals]; and many bodies at one and the same time in one place
[the whole and the parts]; ... And these are but a small part of the
Incongruencies they are forced to, from their disputing
philosophically, instead of admiring, and adoring of the Divine and
Incomprehensible Nature ...."
The real distinction between essence and existence, and that between
form and matter, which served for so long as the basis of metaphysics,
Hobbes identifies as "the Error of Separated Essences." The words
"Is, or Bee, or Are, and the like" add no meaning to an argument nor
do derived words such as "Entity, Essence, Essentially, Essentiality",
which "are the names of nothing" but are mere "Signes" connecting
"one name or attribute to another: as when we say, "a man is a living
body", we mean not that the man is one thing, the living body another,
and the is, or being a third: but that the man, and the living body,
is the same thing; ..." Metaphysiques, Hobbes says, is "far from the
possibility of being understood" and is "repugnant to natural
Being to Hobbes (and the other empiricists) is the physical
The world, (I mean ... the Universe, that is, the whole masse of all
things that are) is corporeall, that is to say, Body; and hath the
dimension of magnitude, namely, Length, Bredth and Depth: also every
part of Body, is likewise Body ... and consequently every part of the
Universe is Body, and that which is not Body, is no part of the
Universe: and because the Universe is all, that which is no part of it
is nothing; and consequently no where."
Hobbes' view is representative of his tradition. As
the categories and the act of existence, and Aquinas the analogy of
being, the rationalists also had their own system, the great chain of
being, an interlocking hierarchy of beings from God to dust.
In addition to the materialism of the empiricists, under the same
aegis of Reason, rationalism produced systems that were diametrically
opposed now called idealism, which denied the reality of matter in
favor of the reality of mind. By a 20th-century classification, the
Hegel and others), are considered the beginning of
continental philosophy, while the empiricists are the beginning, or
the immediate predecessors, of analytical philosophy.
Being in continental philosophy and existentialism
Some philosophers deny that the concept of "being" has any meaning at
all, since we only define an object's existence by its relation to
other objects, and actions it undertakes. The term "I am" has no
meaning by itself; it must have an action or relation appended to it.
This in turn has led to the thought that "being" and nothingness are
closely related, developed in existential philosophy.
Existentialist philosophers such as Sartre, as well as continental
philosophers such as
Hegel and Heidegger have also written extensively
on the concept of being.
Hegel distinguishes between the being of
objects (being in itself) and the being of people (Geist). Hegel,
however, did not think there was much hope for delineating a "meaning"
of being, because being stripped of all predicates is simply nothing.
Heidegger, in his quest to re-pose the original pre-Socratic question
of Being, wondered at how to meaningfully ask the question of the
meaning of being, since it is both the greatest, as it includes
everything that is, and the least, since no particular thing can be
said of it. He distinguishes between different modes of beings: a
privative mode is present-at-hand, whereas beings in a fuller sense
are described as ready-to-hand. The one who asks the question of Being
is described as Da-sein ("there/here-being") or being-in-the-world.
Sartre, popularly understood as misreading Heidegger (an understanding
supported by Heidegger's essay "Letter on Humanism" which responds to
Sartre's famous address, "
Existentialism is a Humanism"), employs
modes of being in an attempt to ground his concept of freedom
ontologically by distinguishing between being-in-itself and
Being is also understood as one's "state of being," and hence its
common meaning is in the context of human (personal) experience, with
aspects that involve expressions and manifestations coming from an
innate "being", or personal character. Heidegger coined the term
"dasein" for this property of being in his influential work
Time ("this entity which each of us is himself…we shall denote by
the term 'dasein.'"), in which he argued that being or dasein links
one's sense of one's body to one's perception of world. Heidegger,
amongst others, referred to an innate language as the foundation of
being, which gives signal to all aspects of being.
Category of being
Cogito ergo sum
Fromm, To Have or to Be?
Hegel, Phenomenology of Spirit
Being and Time
Immanuel Kant, Sapere aude
Sartre, Essays in
Being and Nothingness
^ a b Heidegger, the day Sein und Zeit, p. 27: "this entity which
each of us is himself ... we shall denote by the term 'Dasein'."
^ James, William (1916). Some problems of philosophy: a beginning of
an introduction to philosophy. New York: Longmans, Green and Co.
pp. 38, 40.
^ Aristotle. "
Book VII Section 1 (paragraph 1028b)".
Metaphysics Chapter VII, Section 4 (paragraph 1030a).
Book IX, Chapter 10 (paragraph 1051b).
^ For text of condemnations 1277 (technically still 1276 at the date,
since before 25 of March) see David Piché, La condemnation parisienne
de 1277, , parallel
Latin text with his French translation, or
Latin only with footnotes, by Hans-Georg Lundahl, 
^ Wallace, William A. “
Thomism and Its Opponents.” Dictionary of
the Middle Ages. Ed. Joseph R. Strayer. Vol. 12. New York: Scribner,
1982. 38–45. Print.
^ Wippel, John F. (2000). The metaphysical thought of Thomas Aquinas:
from finite being to uncreated being. Monographs of the Society for
Renaissance Philosophy, No. 1. The Catholic University
of America Press. p. 75.
^ "SUMMA THEOLOGIAE: The names of God (Prima Pars, Q. 13)".
www.newadvent.org. Retrieved 15 March 2018.
^ a b Kreyche 1959, p. 70
^ Aersten, Jan A. (1995), "Aquinas, St. Thomas", in Kim, Jaegwon;
Sosa, Ernest, A companion to metaphysics, Blackwell Companions to
philosophy, pp. 21–22
^ "Iranian Personalities: Sadr Al-Din Mohammad Shirazi".
www.iranchamber.com. Retrieved 15 March 2018.
^ Toofan, M. Zabān ast yā hast?(Language: is or exists?. Ketāb-e
^ "age of reason". dictionary.com. Retrieved 8 January 2009.
^ "empiricism". dictionary.com. Archived from the original on 25
January 2009. Retrieved 9 January 2009.
^ Hobbes 1651, pp. 18, 21–22
^ a b Hobbes 1651, p. 23
^ Hobbes 1651, p. 18
^ Hobbes 1651, p. 501.
^ Hobbes 1651, p. 500.
^ Hobbes 1651, pp. 498–499.
^ Hobbes 1651, pp. 496–497.
^ Hobbes 1651, p. 497.
Gilson, Étienne (1952).
Being and Some Philosophers (2nd corrected
and enlarged ed.). Toronto: Pontifical Institute of Mediaeval Studies
Hobbes, Thomas (1904) . Waller, Alfred Rayney, ed. Leviathan:
or, The matter, forme & power of a commonwealth, ecclesiasticall
and civill. Cambridge: University Press.
Kreyche, Robert J. (1959). First Philosophy: An Introductory Text in
Metaphysics. New York: Holt, Rinehart and Winston.
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Corazzon, Raul (2010). "Theory and History of
Ontology from a
Philosophical Perspective". www.ontology.co. Retrieved 9 October
Ancient Greek philosophical concepts
Apeiron (the unlimited)
Arche (first principle)
Differentia / Genus
Doxa (common opinion)
Dunamis / Energeia (potentiality / actuality)
Hexis (active condition)
Hylomorphism (matter and form)
Hylozoism (matter and life)
Kathēkon (proper function)
Logos (reasoned discourse)
Phronesis (practical wisdom)
Physis (natural law)
Tetractys (fourth triangular number)
Philosophy of psychiatry
Philosophy of perception
Space and time
Schools of thought
Acintya bheda abheda
Foundationalism / Coherentism
Internalism and Externalism
Ordinary language philosophy
Rationalism / Reasonism
Philosophy by region
Women in philosophy
Georg W. F. Hegel
Gottfried Wilhelm Leibniz
Charles Sanders Peirce
Alfred N. Whitehead
G. E. Moore
P. F. Strawson
R. G. Collingwood
Willard V. O. Quine
G. E. M. Anscombe
David Malet Armstrong
Peter van Inwagen
Abstract object theory
Meaning of life
Pirsig's metaphysics of Quality
Category of being
Cogito ergo sum
Identity and change
Interpretations of quantum mechanics
Philosophy of mind
Philosophy of psychology
Philosophy of self
Philosophy of space and time