Being and existence in philosophy are related and somewhat
overlapping with respect to their meanings. Classical Greek had no
independent word of "existence." The word "existence," as distinguished
from the word "being," arose in the Middle Ages. Influenced by Islamic
philosophy that recognized the contingency of the created world as
compared with God the Creator, Christian philosophers such as Thomas
Aquinas used the Latin word "existere" ("to exist" or "to appear") as distinct from "esse" ("to be") or "essentia"
("essence"). The Medieval distinction between essence and existence in
the world, however, was critiqued by later theologians and philosophers
for various reasons.
Modern existentialism maintained the distinction between essence and
existence, but reversed the Medieval priority of essence over existence.
The German philosopher Martin Heidegger, who critiqued the Thomistic
theory of the causal relationship of difference between God and the
world as well as its related theory of the distinction between essence
and existence, dealt with the question of being in a very new way that
involved the human being as Dasein ("being-there"), which to him is synonymous with existence.
The majority of analytic philosophers have rejected the distinction of
being and existence. But, for philosophers and theologians who consider
the distinction between being and existence an important one, there are
two significant issues: teleology and individuation or embodiment. For
what purpose do individual things exist? How do things become individual
embodiments of their corresponding universals? A notable approach to
the first issue was proposed by the American theologian Schubert Ogden,
who combined existentialism with process theism to explain the unity of
reality centering on God's aim. The Spanish Jesuit Francisco Suárez
approached the second issue by proposing that the form and matter of a
substance in union determine the individuality of that embodied
substance.
Relationship of being and existence
Greek philosophy
History shows a rather complex relationship between being and existence.
The classical Greek equivalent of the English verb "be" was "einai,"
but there seems to have been no classical Greek equivalent of the
English verb "exist." It was only in the Middle Ages that the Latin word
"exsistere" was made from a combination of "ex" ("out of") and "sistere"
("to cause to stand") to mean "to exist," "to appear," or "to emerge."
The reason why classical Greek did not have any distinct concept of
"exist" was that in Greek philosophy from Parmenides to Aristotle the
primary project was a veridical one of articulating truthfulness in
reality through copula sentences of the form "X is Y." The theory of
predication was central, and the theory of existence peripheral. So,
even when Greek philosophers wanted to express the concept of existence,
they did so only in the predicative form; "X exists" was expressed as
"X is something." Thus, the word "einai" ("be") had to be used more widely than its predicative meaning. It was in the context of this wider use of "einai" ("be") that Aristotle referred to the concept of existence as "hoti esti" ("that it is") as distinguished from "ti esti" ("what it is"), which would mean essence.
Of course, in late Greek philosophy the old Greek verb "hyparkein"
(originally, "to make a beginning") started to be used non-technically
to mean "to exist"; but, it and its early Latin rendering "exsistere" still continued somewhat ambiguously to retain the predicative meaning as well, and furthermore the use of the noun exsistentia ("existence") was not popular yet.
Medieval Christian philosophy
Eventually, however, the concept of "existentia" ("existence")
was established amongst Medieval Christian philosophers such as St.
Thomas Aquinas as a technical term contrasted with "essentia" ("essence"), an abstract form of the presumed present participle of "esse"
("to be"). While essence apparently meant "what a thing is," existence
meant "that a thing exists." According to Charles H. Khan, this
development of the modern sense of existence occurred under the
influence of Islamic philosophy, which distinguished existence (wujud) from essence (mahiat)
in its radical revision of Greek ontology in light of a biblical
metaphysics of creation within Islam which distinguished the created
world (contingency) from God (necessity). Thomas adopted this,
maintaining that the essence and existence of each and every contingent,
finite creature are distinct, while essence and existence are identical
within God, who is therefore preeminent over the world. According to
him, God causes each and every finite creature to "exist" with its
"essence."
Thomas, however, indicated this causal relationship of difference between God and the world in terms of the "analogia entis" ("analogy of being"), referring to God and each finite creature as "ipsum esse subsistens" (Self-subsistent Being) and "ens" (being), respectively. This means that in spite of the development of "existentia" ("existence") as a new word with a distinctive meaning in the Middle Ages, still the term "esse"
("to be") was used more generally to cover the meaning of existence as
well. Modern existentialism's emphasis upon the priority of existence
over essence was still alien.
Later criticisms of the Thomistic position
The Thomistic distinction between essence and existence in the created
world was criticized by later theologians and philosophers for various
reasons. Critics include Duns Scotus, Francisco Suárez, René Descartes,
Gottfried Leibniz, David Hume, and Immanuel Kant. But, especially
existentialim's criticism was notable because of its attempt to reverse
the order of priority between essence and existence. Søren Kierkegaard
denied the importance of the objective essence of a thing in favor of
the subjective appropriation of it. He, thus, held that there is no
truth in objective knowledge of essence itself, and that the truth about
reality is revealed only in the human subject's "passion of the
infinite" as a believer. In talking about the essence and existence of a
human being, Jean-Paul Sartre, for whom existentialism meant an
atheistic humanism, went so far as to say that because there is no
Creator, existence precedes essence.
The most notable critic, however, was the German philosopher Martin
Heidegger. According to Heidegger, Thomas' theory of the causal
relationship of difference between God and the world through the analogy
of being, and his related theory of the distinction between essence and
existence in the world, are far from answering the fundamental question
of the meaning of being, which was not answered in the long
philosophical tradition in the West anyway because being itself was
taken for granted as self-evident or undefinable. Therefore, in order to
let the human being constantly pursue the question of "being" (Sein), Heidegger referred to that human being as "Dasein" (literally "being-there"), who, as a "being-in-the-world" (In-der-Welt-sein) thrown out to the temporal and phenomenological world of "beings" (Seiendes),
is faced with angst and mortality there, but who nevertheless is
expected to experience authenticity by standing in the openness of
"being" in the midst of "beings." Here, the sense of "being" to be
experienced is pre-conceptual and non-propositional in the everyday
situation of human life; and the causal relationship of difference
between God as "Self-subsistent Being" (ipsum esse subsistens) and the created world of "beings" (ens) in Thomas' metaphysics is superseded by the distinction between "being" (Sein) and "beings" (Seiendes) in Heidegger's phenomenological ontology in pursuit of the meaning of "being." For Heidegger, the word "existence" (Existenz) is simply synonymous with Dasein: "The 'essence' of Dasein lies in its existence."
Being and existence in analytic philosophy
Actualism
Many analytic philosophers in the twentieth century such as Gottlob
Frege, Bertrand Russell, and W.V. Quine, believed that being and
existence are identical, that is, that what there is, is precisely what
exists. It is basically so-called "actualism," and it maintains that
there is no kind of being beyond actual existence. The identity of being
and existence also means that every predicative proposition can be
translated into an existential one without changing meaning. For
example, adding "exists" to "a wise man" to give the complete sentence
"A wise man exists" has the same effect as joining "some man" to "wise"
using the copula to say "Some man is wise." So, the "exists" of the
existential proposition takes the place of the copula. This view is the
basis of the dominant position in modern Anglo-American analytic
philosophy: that existence is asserted by the existential quantifier.
Possibilism
Of course, there is a school called "possibilism," which distinguishes
between being and existence, that is, between what there is and what
exists, saying that the latter comprises a relatively small portion of
the former. According to this, although there are things that actually
exist, there are also things that do not exist: they are what there
merely are, not having existence or actuality, which only
things that actually exist have. Such things are non-existent possible
things like Santa Claus, unicorns, aliens, and people that were never
born. They could have actually existed, but as it happens, they simply
do not. To this possibilist realm of the non-existent, some of the
followers of Alexius Meinong such as Terence Parsons would add
impossible objects like square circles and wooden iron, which have
contradictory properties.
Adjusted possibilism
But, scholars such as Quine, for whom there is no distinction between
being and existence, have critiqued possibilism, by saying that we
cannot embrace non-actual possible objects since there is no real
criterion of identity for them: "No entity without identity." This
critique from Quine has given rise to an adjusted version of
possibilism, which now agrees that being and existence are identical,
saying that everything there is exists, but which nevertheless insists
that not everything that exists is actual, that is, that there exist
things that fail to be actual. This, however, looks like a word game,
simply renaming being as "existence" and existence as "actuality." Thus,
a more advanced version of possibilism, which takes Quine's objection
more seriously, has been developed by David Kellogg Lewis.
Modal realism
While agreeing with the adjusted version just mentioned above that being
and existence are identical, but that actuality is to be distinguished
from existence, Lewis has a new understanding of actuality, treating it
in terms of relation. Thus, according to Lewis, when people say
that there are things that exist but are not actual, it means that there
are things that are spatiotemporally unrelated to the world, although
they exist in a full-fledged sense in other worlds. The word "actual,"
then, is an indexical, whose reference on any given occasion of
utterance is determined by the context or world in which the utterance
occurs. So, when one utter, "New York City is actual" (or more
naturally, "New York City actually exists"), its truthfulness is made
not because actuality is some intrinsic property of New York City but
rather because New York City occupies the same world as the speaker.
Lewis' version of possibilism is sometimes called "modal realism," and
it is quite Quinean.
Different realms of reality
The issue on whether or not there are different worlds or realms of
reality is not new. Ancient Greek philosophy observed that there are
concrete, material beings in the spatiotemporal world in the sense of
physical reality which is detectable by physical senses or physical
instruments, while there are also ideas and values such as love,
justice, and good which however are not of the same physically sensible
material. For Plato, those ideas and values in an incorporeal realm of
the world are real beings because they are self-existent and immutable,
while material beings in the corporeal world are merely their ephemeral
"shadows" far from real beings. For Aristotle, by contrast, only
individual things called substances in the spatiotemporal world are
fully existent beings, and other beings, called categories, such as
relation, quantity, time and place, and Plato's ideas and values, have a
derivative kind of being, dependent on those individual things. In the
Middle Ages, based upon a biblical metaphysics of creation, the notion
of existence was established to show the emergence of the created world,
distinguishable from being in general and also from essence.
The Plato-Aristotle tension above was echoed in the Medieval controversy
between realism and nominalism. The approach of realists was to argue
that the sentence "Socrates is wise," which contains a noun reference
only for "Socrates," can be rewritten as "Socrates has wisdom," which
apparently proves the existence of a reference for "wisdom" as well.
This argument, however, was inverted by nominalists such as William of
Ockham in arguing that "Socrates has wisdom" can be rewritten as
"Socrates is wise," which contains a reference only for "Socrates." The
nominalist method has basically been inherited in analytic philosophy,
which holds that there is hardly any kind of being beyond actual
existence.
Teleology, being, and existence
The teleological nature of reality was discussed by Plato and Aristotle.
Plato identified the Idea of the Good as the ultimate cause or measure
in the whole of reality, saying that things that are gain their
usefulness or value from it. Aristotle maintained that each substance
has its final cause, which guides it throughout various changes it goes
through to reach what it is. According to him, the final cause is
virtually identical with the formal and efficient causes because all
these can be attributed to the form of each substance, which is immanent
in it, although God as "pure form" is the ultimate final, formal, and
efficient cause, towards which all things tend. This teleological
approach does not believe that the final causes of different substances
are incompatible with one other, but rather that they are for one
another. Hence, "extrinsic finality," through which the harmonious
relationship of different individuals is made possible, is distinguished
from the "intrinsic finality" of each individual, through which it is
directed towards what it is. Aristotle's teleology was inherited to the
creationist theology of Thomas Aquinas and others in the Catholic
Church.
With the coming of the modern period, philosophers began to question
teleology. Francis Bacon and René Descartes cautioned against the
abusive attribution of Aristotelian final causes to various things and
events. One of the few exceptions was Gottfried Leibniz' notion of
"pre-established harmony" of monads programmed by God. Immanuel Kant
rejected not only the Aristotelian teleology of nature, but also the
possibility of traditional metaphysics itself. Kant limited teleology to
the subjective realm of mind and explored its possibility within the
realms of ethics and aesthetics. Although Hegel temporally revived
teleology in his speculative metaphysics, most post-Hegelian
philosophers were not interested in ontology with its teleology of
nature.
Analytic philosophers refused metaphysics itself and limited the
question of teleology to the realm of conceptual analysis of languages.
However, in the twentieth century, Martin Heidegger brought back
ontology as a central question of philosophy. Combining the two trends
of thought of his time, phenomenology and hermeneutics, Heidegger
developed ontology as a hermeneutic phenomenology. Within the framework
of hermeneutic phenomenology, which still incorporated the Kantian
skepticism of speculative metaphysics, he discussed the teleology of
being, conceptualizing the interconnected mode of human existence as
"being-in-the-world" (In-der-Welt-sein).
Also with the emergence and development of existentialism, the question
of the purposiveness, value, and relatedness of being has been addressed
in a new way. Martin Buber, for example, dealt with it in the context
of the "I-Thou" relationship. Gabriel Marcel came up with the mutual,
communal activity of being. However, although Buber and Marcel were
theists, existentialism in general has often been critiqued of being
fundamentally humanistic. Therefore, any teleology or theory of value
developed by existentialism, no matter how insightful it may sound, has
tended to be blamed for being self-made. At the same time, traditional
Aristotelian teleology has been criticized of not being able to
successfully establish the true relations not only amongst different
individual substances but also between them and God because of the
Aristotelian notion of God as self-contained "pure form" or "unmoved
mover." To address these possible weaknesses of both existentialism and
Aristotelianism, Schubert Ogden proposed to link the experiencing human
subject in existentialism and the experiencing God of dipolarity in
process thought, hoping that the linkage of existentialist humanism and
process theism in this regard would bring in a situation in which the
unity of the whole of reality is realized centering on God's aim.
Existence as individuation or embodiment
The world of phenomena is the world where many particular things exist.
Each particular thing is considered to have been developed or determined
from its corresponding category or universal idea. The universal idea,
then, is considered to have been individuated or embodied in that
particular thing.
Catholic philosophy
Medieval Catholic philosophy dealt with the issue of individuation.
According to Thomas Aquinas, the cause of individuation is matter,
because different horses, for example, result when their common
universal idea of "horseness" is individuated by matter in each of them.
It is just like today many different cars of the same model come into
existence when its common mold is stamped to materials, which therefore
turn out to be the cause of individuation. Thomas called matter with
this function "materia quantitate signata" ("matter signed in
quantity"). According to Duns Scotus, however, formless matter, which is
itself indeterminate, cannot serve to make "horseness" into this horse
or that horse. Although horseness itself may be common and repeatable,
the horseness of this horse is to be distinguished from that of that
horse. Scotus held, therefore, that individuation is caused by a
determination called a haecceitas ("thisness"). It is not a bare
particular in the sense of a substance but rather a non-qualitative
property of a substance. It is something like a form. Francisco Suárez, a
Spanish Jesuit philosopher in the late sixteenth and early seventeenth
century, went one step further, by maintaining that the principle of
individuation is both this matter and this form of a substance in
union, although the form is the chief principle: "adaequatum
individuationis principium esse hanc materiam et hanc formam inter se
unitas, inter quae praecipuum principium est forma."
Religion
In many religions such as Hinduism, Taoism, Confucianism, and
Christianity, enlightened people are considered to be individual
embodiments of universal truth. Concrete existence is understood to have
an intricate relationship with truth. Daoism, for example, sees Lao Tzu
as the embodiment of Tao. In Christianity, Jesus said, "I am the
way and the truth and the life. No one comes to the Father except
through me." (John 14:6). Here, truth is even understood not as some
kind of property or object one can possess or lose, but as existence
itself. So, Jesus did not say, "I have the truth," but "I am the truth."
Christian theology identifies him as the Logos Incarnate. Avatamsaka Sutra in Buddhism describes the world as the manifestation of truth.