Empiricism is a theory which states that knowledge
comes only or primarily from sensory experience.
One of several views of epistemology, the
study of human knowledge, along with rationalism
and skepticism, empiricism emphasizes the
role of experience and evidence, especially
sensory experience, in the formation of ideas,
over the notion of innate ideas or traditions;
empiricists may argue however that traditions
arise due to relations of previous sense experiences.
Empiricism in the philosophy of science emphasizes
evidence, especially as discovered in experiments.
It is a fundamental part of the scientific
method that all hypotheses and theories must
be tested against observations of the natural
world rather than resting solely on a priori
reasoning, intuition, or revelation.
Empiricism, often used by natural scientists,
asserts that "knowledge is based on experience"
and that "knowledge is tentative and probabilistic,
subject to continued revision and falsification."
One of the epistemological tenets is that
sensory experience creates knowledge.
The scientific method, including experiments
and validated measurement tools, guides empirical
research.
Etymology
The English term "empirical" derives from
the Greek word ἐμπειρία, which is
cognate with and translates to the Latin experientia,
from which we derive the word "experience"
and the related "experiment".
The term was used by the Empiric school of
ancient Greek medical practitioners, who rejected
the three doctrines of the Dogmatic school,
preferring to rely on the observation of "phenomena".
History
Background
A central concept in science and the scientific
method is that it must be empirically based
on the evidence of the senses.
Both natural and social sciences use working
hypotheses that are testable by observation
and experiment.
The term semi-empirical is sometimes used
to describe theoretical methods that make
use of basic axioms, established scientific
laws, and previous experimental results in
order to engage in reasoned model building
and theoretical inquiry.
Philosophical empiricists hold no knowledge
to be properly inferred or deduced unless
it is derived from one's sense-based experience.
This view is commonly contrasted with rationalism,
which states that knowledge may be derived
from reason independently of the senses.
For example John Locke held that some knowledge
could be arrived at through intuition and
reasoning alone.
Similarly Robert Boyle, a prominent advocate
of the experimental method, held that we have
innate ideas.
The main continental rationalists were also
advocates of the empirical "scientific method".
Early empiricism
The notion of tabula rasa connotes a view
of mind as an originally blank or empty recorder
on which experience leaves marks.
This denies that humans have innate ideas.
The image dates back to Aristotle;
What the mind thinks must be in it in the
same sense as letters are on a tablet which
bears no actual writing; this is just what
happens in the case of the mind..
Aristotle's explanation of how this was possible,
was not strictly empiricist in a modern sense,
but rather based on his theory of potentiality
and actuality, and experience of sense perceptions
still requires the help of the active nous.
These notions contrasted with Platonic notions
of the human mind as an entity that pre-existed
somewhere in the heavens, before being sent
down to join a body on Earth.
Aristotle was considered to give a more important
position to sense perception than Plato, and
commentators in the middle ages summarized
one of his positions as "nihil in intellectu
nisi prius fuerit in sensu".
During the middle ages Aristotle's theory
of tabula rasa was developed by Islamic philosophers
starting with Al Farabi, developing into an
elaborate theory by Avicenna and demonstrated
as a thought experiment by Ibn Tufail.
For Avicenna, for example, the tabula rasa
is a pure potentiality that is actualized
through education, and knowledge is attained
through "empirical familiarity with objects
in this world from which one abstracts universal
concepts" developed through a "syllogistic
method of reasoning in which observations
lead to propositional statements which when
compounded lead to further abstract concepts."
The intellect itself develops from a material
intellect, which is a potentiality "that can
acquire knowledge to the active intellect,
the state of the human intellect in conjunction
with the perfect source of knowledge".
So the immaterial "active intellect", separate
from any individual person, is still essential
for understanding to occur.
In the 12th century CE the Andalusian Muslim
philosopher and novelist Abu Bakr Ibn Tufail
included the theory of tabula rasa as a thought
experiment in his Arabic philosophical novel,
Hayy ibn Yaqdhan in which he depicted the
development of the mind of a feral child "from
a tabula rasa to that of an adult, in complete
isolation from society" on a desert island,
through experience alone.
The Latin translation of his philosophical
novel, entitled Philosophus Autodidactus,
published by Edward Pococke the Younger in
1671, had an influence on John Locke's formulation
of tabula rasa in An Essay Concerning Human
Understanding.
A similar Islamic theological novel, Theologus
Autodidactus, was written by the Arab theologian
and physician Ibn al-Nafis in the 13th century.
It also dealt with the theme of empiricism
through the story of a feral child on a desert
island, but departed from its predecessor
by depicting the development of the protagonist's
mind through contact with society rather than
in isolation from society.
During the 13th century Thomas Aquinas adopted
the Aristotelian position that the senses
are essential to mind into scholasticism.
Bonaventure, one of Aquinas' strongest intellectual
opponents, offered some of the strongest arguments
in favour of the Platonic idea of the mind.
Renaissance Italy
In the late renaissance various writers began
to question the medieval and classical understanding
of knowledge acquisition in a more fundamental
way.
In political and historical writing Niccolò
Machiavelli and his friend Francesco Guicciardini
initiated a new realistic style of writing.
Machiavelli in particular was scornful of
writers on politics who judged everything
in comparison to mental ideals and demanded
that people should study the "effectual truth"
instead.
Their contemporary, Leonardo da Vinci said,
If you find from your own experience that
something is a fact and it contradicts what
some authority has written down, then you
must abandon the authority and base your reasoning
on your own findings.
The decidedly anti-Aristotelian and anti-clerical
music theorist Vincenzo Galilei, father of
Galileo and the inventor of monody, made use
of the method in successfully solving musical
problems, firstly, of tuning such as the relationship
of pitch to string tension and mass in stringed
instruments, and to volume of air in wind
instruments; and secondly to composition,
by his various suggestions to composers in
his Dialogo della musica antica e moderna.
The Italian word he used for "experiment"
was esperienza.
It is known that he was the essential pedagogical
influence upon the young Galileo, his eldest
son, arguably one of the most influential
empiricists in history.
Vincenzo, through his tuning research, found
the underlying truth at the heart of the misunderstood
myth of 'Pythagoras' hammers', and through
this and other discoveries that demonstrated
the fallibility of traditional authorities,
a radically empirical attitude developed,
passed on to Galileo, which regarded "experience
and demonstration" as the sine qua non of
valid rational enquiry.
British empiricism
British empiricism, though it was not a term
used at the time, derives from the 17th century
period of early modern philosophy and modern
science.
The term became useful in order to describe
differences perceived between two of its founders
Francis Bacon, described as empiricist, and
René Descartes, who is described as a rationalist.
Thomas Hobbes and Baruch Spinoza, in the next
generation, are often also described as an
empiricist and a rationalist respectively.
John Locke, George Berkeley, and David Hume
were the primary exponents of empiricism in
the 18th century Enlightenment, with Locke
being the person who is normally known as
the founder of empiricism as such.
In response to the early-to-mid-17th century
"continental rationalism" John Locke proposed
in An Essay Concerning Human Understanding
a very influential view wherein the only knowledge
humans can have is a posteriori, i.e., based
upon experience.
Locke is famously attributed with holding
the proposition that the human mind is a tabula
rasa, a "blank tablet," in Locke's words "white
paper," on which the experiences derived from
sense impressions as a person's life proceeds
are written.
There are two sources of our ideas: sensation
and reflection.
In both cases, a distinction is made between
simple and complex ideas.
The former are unanalysable, and are broken
down into primary and secondary qualities.
Primary qualities are essential for the object
in question to be what it is.
Without specific primary qualities, an object
would not be what it is.
For example, an apple is an apple because
of the arrangement of its atomic structure.
If an apple was structured differently, it
would cease to be an apple.
Secondary qualities are the sensory information
we can perceive from its primary qualities.
For example, an apple can be perceived in
various colours, sizes, and textures but it
is still identified as an apple.
Therefore its primary qualities dictate what
the object essentially is, while its secondary
qualities define its attributes.
Complex ideas combine simple ones, and divide
into substances, modes, and relations.
According to Locke, our knowledge of things
is a perception of ideas that are in accordance
or discordance with each other, which is very
different from the quest for certainty of
Descartes.
A generation later, the Irish Anglican bishop,
George Berkeley, determined that Locke's view
immediately opened a door that would lead
to eventual atheism.
In response to Locke, he put forth in his
Treatise Concerning the Principles of Human
Knowledge an important challenge to empiricism
in which things only exist either as a result
of their being perceived, or by virtue of
the fact that they are an entity doing the
perceiving..
In his text Alciphron, Berkeley maintained
that any order humans may see in nature is
the language or handwriting of God.
Berkeley's approach to empiricism would later
come to be called subjective idealism.
The Scottish philosopher David Hume responded
to Berkeley's criticisms of Locke, as well
as other differences between early modern
philosophers, and moved empiricism to a new
level of skepticism.
Hume argued in keeping with the empiricist
view that all knowledge derives from sense
experience, but he accepted that this has
implications not normally acceptable to philosophers.
He wrote for example, "Mr. Locke divides all
arguments into demonstrative and probable.
In this view, we must say, that it is only
probable all men must die, or that the sun
will rise to-morrow."
And, "Mr. Locke, in his chapter of power,
says that, finding from experience, that there
are several new productions in nature, and
concluding that there must somewhere be a
power capable of producing them, we arrive
at last by this reasoning at the idea of power.
But no reasoning can ever give us a new, original,
simple idea; as this philosopher himself confesses.
This, therefore, can never be the origin of
that idea."
Hume divided all of human knowledge into two
categories: relations of ideas and matters
of fact.
Mathematical and logical propositions are
examples of the first, while propositions
involving some contingent observation of the
world are examples of the second.
All of people's "ideas", in turn, are derived
from their "impressions".
For Hume, an "impression" corresponds roughly
with what we call a sensation.
To remember or to imagine such impressions
is to have an "idea".
Ideas are therefore the faint copies of sensations.
Hume maintained that all knowledge, even the
most basic beliefs about the natural world,
cannot be conclusively established by reason.
Rather, he maintained, our beliefs are more
a result of accumulated habits, developed
in response to accumulated sense experiences.
Among his many arguments Hume also added another
important slant to the debate about scientific
method — that of the problem of induction.
Hume argued that it requires inductive reasoning
to arrive at the premises for the principle
of inductive reasoning, and therefore the
justification for inductive reasoning is a
circular argument.
Among Hume's conclusions regarding the problem
of induction is that there is no certainty
that the future will resemble the past.
Thus, as a simple instance posed by Hume,
we cannot know with certainty by inductive
reasoning that the sun will continue to rise
in the East, but instead come to expect it
to do so because it has repeatedly done so
in the past.
Hume concluded that such things as belief
in an external world and belief in the existence
of the self were not rationally justifiable.
According to Hume these beliefs were to be
accepted nonetheless because of their profound
basis in instinct and custom.
Hume's lasting legacy, however, was the doubt
that his skeptical arguments cast on the legitimacy
of inductive reasoning, allowing many skeptics
who followed to cast similar doubt.
Phenomenalism
Most of Hume's followers have disagreed with
his conclusion that belief in an external
world is rationally unjustifiable, contending
that Hume's own principles implicitly contained
the rational justification for such a belief,
that is, beyond being content to let the issue
rest on human instinct, custom and habit.
According to an extreme empiricist theory
known as Phenomenalism, anticipated by the
arguments of both Hume and George Berkeley,
a physical object is a kind of construction
out of our experiences.
Phenomenalism is the view that physical objects,
properties, events are reducible to mental
objects, properties, events.
Ultimately, only mental objects, properties,
events, exist — hence the closely related
term subjective idealism.
By the phenomenalistic line of thinking, to
have a visual experience of a real physical
thing is to have an experience of a certain
kind of group of experiences.
This type of set of experiences possesses
a constancy and coherence that is lacking
in the set of experiences of which hallucinations,
for example, are a part.
As John Stuart Mill put it in the mid-19th
century, matter is the "permanent possibility
of sensation".
Mill's empiricism went a significant step
beyond Hume in still another respect: in maintaining
that induction is necessary for all meaningful
knowledge including mathematics.
As summarized by D.W.
Hamlin:
[Mill] claimed that mathematical truths were
merely very highly confirmed generalizations
from experience; mathematical inference, generally
conceived as deductive [and a priori] in nature,
Mill set down as founded on induction.
Thus, in Mill's philosophy there was no real
place for knowledge based on relations of
ideas.
In his view logical and mathematical necessity
is psychological; we are merely unable to
conceive any other possibilities than those
that logical and mathematical propositions
assert.
This is perhaps the most extreme version of
empiricism known, but it has not found many
defenders.
Mill's empiricism thus held that knowledge
of any kind is not from direct experience
but an inductive inference from direct experience.
The problems other philosophers have had with
Mill's position center around the following
issues: Firstly, Mill's formulation encounters
difficulty when it describes what direct experience
is by differentiating only between actual
and possible sensations.
This misses some key discussion concerning
conditions under which such "groups of permanent
possibilities of sensation" might exist in
the first place.
Berkeley put God in that gap; the phenomenalists,
including Mill, essentially left the question
unanswered.
In the end, lacking an acknowledgement of
an aspect of "reality" that goes beyond mere
"possibilities of sensation", such a position
leads to a version of subjective idealism.
Questions of how floor beams continue to support
a floor while unobserved, how trees continue
to grow while unobserved and untouched by
human hands, etc., remain unanswered, and
perhaps unanswerable in these terms.
Secondly, Mill's formulation leaves open the
unsettling possibility that the "gap-filling
entities are purely possibilities and not
actualities at all".
Thirdly, Mill's position, by calling mathematics
merely another species of inductive inference,
misapprehends mathematics.
It fails to fully consider the structure and
method of mathematical science, the products
of which are arrived at through an internally
consistent deductive set of procedures which
do not, either today or at the time Mill wrote,
fall under the agreed meaning of induction.
The phenomenalist phase of post-Humean empiricism
ended by the 1940s, for by that time it had
become obvious that statements about physical
things could not be translated into statements
about actual and possible sense data.
If a physical object statement is to be translatable
into a sense-data statement, the former must
be at least deducible from the latter.
But it came to be realized that there is no
finite set of statements about actual and
possible sense-data from which we can deduce
even a single physical-object statement.
Remember that the translating or paraphrasing
statement must be couched in terms of normal
observers in normal conditions of observation.
There is, however, no finite set of statements
that are couched in purely sensory terms and
can express the satisfaction of the condition
of the presence of a normal observer.
According to phenomenalism, to say that a
normal observer is present is to make the
hypothetical statement that were a doctor
to inspect the observer, the observer would
appear to the doctor to be normal.
But, of course, the doctor himself must be
a normal observer.
If we are to specify this doctor's normality
in sensory terms, we must make reference to
a second doctor who, when inspecting the sense
organs of the first doctor, would himself
have to have the sense data a normal observer
has when inspecting the sense organs of a
subject who is a normal observer.
And if we are to specify in sensory terms
that the second doctor is a normal observer,
we must refer to a third doctor, and so on.
Logical empiricism
Logical empiricism was an early 20th-century
attempt to synthesize the essential ideas
of British empiricism with certain insights
from mathematical logic that had been developed
by Gottlob Frege and Ludwig Wittgenstein.
Some of the key figures in this movement were
Otto Neurath, Moritz Schlick and the rest
of the Vienna Circle, along with A.J.
Ayer, Rudolf Carnap and Hans Reichenbach.
The neopositivists subscribed to a notion
of philosophy as the conceptual clarification
of the methods, insights and discoveries of
the sciences.
They saw in the logical symbolism elaborated
by Frege and Bertrand Russell a powerful instrument
that could rationally reconstruct all scientific
discourse into an ideal, logically perfect,
language that would be free of the ambiguities
and deformations of natural language.
This gave rise to what they saw as metaphysical
pseudoproblems and other conceptual confusions.
By combining Frege's thesis that all mathematical
truths are logical with the early Wittgenstein's
idea that all logical truths are mere linguistic
tautologies, they arrived at a twofold classification
of all propositions: the analytic and the
synthetic.
On this basis, they formulated a strong principle
of demarcation between sentences that have
sense and those that do not: the so-called
verification principle.
Any sentence that is not purely logical, or
is unverifiable is devoid of meaning.
As a result, most metaphysical, ethical, aesthetic
and other traditional philosophical problems
came to be considered pseudoproblems.
In the extreme empiricism of the neopositivists—at
least before the 1930s—any genuinely synthetic
assertion must be reducible to an ultimate
assertion that expresses direct observations
or perceptions.
In later years, Carnap and Neurath abandoned
this sort of phenomenalism in favor of a rational
reconstruction of knowledge into the language
of an objective spatio-temporal physics.
That is, instead of translating sentences
about physical objects into sense-data, such
sentences were to be translated into so-called
protocol sentences, for example, "X at location
Y and at time T observes such and such."
The central theses of logical positivism came
under sharp attack after World War 2 by thinkers
such as Nelson Goodman, W.V.
Quine, Hilary Putnam, Karl Popper, and Richard
Rorty.
By the late 1960s, it had become evident to
most philosophers that the movement had pretty
much run its course, though its influence
is still significant among contemporary analytic
philosophers such as Michael Dummett and other
anti-realists.
Pragmatism
In the late 19th and early 20th century several
forms of pragmatic philosophy arose.
The ideas of pragmatism, in its various forms,
developed mainly from discussions that took
place while Charles Sanders Peirce and William
James were both at Harvard in the 1870s.
James popularized the term "pragmatism", giving
Peirce full credit for its patrimony, but
Peirce later demurred from the tangents that
the movement was taking, and redubbed what
he regarded as the original idea with the
name of "pragmaticism".
Along with its pragmatic theory of truth,
this perspective integrates the basic insights
of empirical and rational thinking.
Charles Peirce was highly influential in laying
the groundwork for today's empirical scientific
method.
Although Peirce severely criticized many elements
of Descartes' peculiar brand of rationalism,
he did not reject rationalism outright.
Indeed, he concurred with the main ideas of
rationalism, most importantly the idea that
rational concepts can be meaningful and the
idea that rational concepts necessarily go
beyond the data given by empirical observation.
In later years he even emphasized the concept-driven
side of the then ongoing debate between strict
empiricism and strict rationalism, in part
to counterbalance the excesses to which some
of his cohorts had taken pragmatism under
the "data-driven" strict-empiricist view.
Among Peirce's major contributions was to
place inductive reasoning and deductive reasoning
in a complementary rather than competitive
mode, the latter of which had been the primary
trend among the educated since David Hume
wrote a century before.
To this, Peirce added the concept of abductive
reasoning.
The combined three forms of reasoning serve
as a primary conceptual foundation for the
empirically based scientific method today.
Peirce's approach "presupposes that the objects
of knowledge are real things, the characters
of real things do not depend on our perceptions
of them, and everyone who has sufficient experience
of real things will agree on the truth about
them.
According to Peirce's doctrine of fallibilism,
the conclusions of science are always tentative.
The rationality of the scientific method does
not depend on the certainty of its conclusions,
but on its self-corrective character: by continued
application of the method science can detect
and correct its own mistakes, and thus eventually
lead to the discovery of truth".
In his Harvard "Lectures on Pragmatism", Peirce
enumerated what he called the "three cotary
propositions of pragmatism", saying that they
"put the edge on the maxim of pragmatism".
First among these he listed the peripatetic-thomist
observation mentioned above, but he further
observed that this link between sensory perception
and intellectual conception is a two-way street.
That is, it can be taken to say that whatever
we find in the intellect is also incipiently
in the senses.
Hence, if theories are theory-laden then so
are the senses, and perception itself can
be seen as a species of abductive inference,
its difference being that it is beyond control
and hence beyond critique – in a word, incorrigible.
This in no way conflicts with the fallibility
and revisability of scientific concepts, since
it is only the immediate percept in its unique
individuality or "thisness" – what the Scholastics
called its haecceity – that stands beyond
control and correction.
Scientific concepts, on the other hand, are
general in nature, and transient sensations
do in another sense find correction within
them.
This notion of perception as abduction has
received periodic revivals in artificial intelligence
and cognitive science research, most recently
for instance with the work of Irvin Rock on
indirect perception.
Around the beginning of the 20th century,
William James coined the term "radical empiricism"
to describe an offshoot of his form of pragmatism,
which he argued could be dealt with separately
from his pragmatism – though in fact the
two concepts are intertwined in James's published
lectures.
James maintained that the empirically observed
"directly apprehended universe needs ... no
extraneous trans-empirical connective support",
by which he meant to rule out the perception
that there can be any value added by seeking
supernatural explanations for natural phenomena.
James's "radical empiricism" is thus not radical
in the context of the term "empiricism", but
is instead fairly consistent with the modern
use of the term "empirical".
John Dewey modified James' pragmatism to form
a theory known as instrumentalism.
The role of sense experience in Dewey's theory
is crucial, in that he saw experience as unified
totality of things through which everything
else is interrelated.
Dewey's basic thought, in accordance with
empiricism was that reality is determined
by past experience.
Therefore, humans adapt their past experiences
of things to perform experiments upon and
test the pragmatic values of such experience.
The value of such experience is measured experientially
and scientifically, and the results of such
tests generate ideas that serve as instruments
for future experimentation, in physical sciences
as in ethics.
Thus, ideas in Dewey's system retain their
empiricist flavour in that they are only known
a posteriori.
See also
Endnotes
References
External links
Rationalism vs. Empiricism entry in the Stanford
Encyclopedia of Philosophy
Rationalism vs. Empiricism at the Indiana
Philosophy Ontology Project
Empiricism on In Our Time at the BBC.
Empiricism
Theory of Knowledge: An Introduction to Empiricism
