Epistemology and methodology: main trends and ends. (Эпистемология и Методология)
ICEF, GROUP 3,
ENGLISH GROUP 1.
ESSAY IN PHILOSOPHY
EPISTEMOLOGY AND METHODOLOGY: MAIN TRENDS
Международный Институт Экономики и Финансов, 1 курс,
Высшая школа экономики.
TABLE OF CONTENTS:
3. Epistemology as
7. Some Mental
Activities Common to All Methods.
8. Observation and
9. Analysis and
Supposition and Idealisation.
and deductive methods.
16. RELATION OF
EPISTEMOLOGY TO OTHER BRANCHES OF PHILOSOPHY
Epistemology is one of
the main branches of philosophy; its subject matter concerns the nature,
origin, scope, and limits of human knowledge. The name is derived from the
Greek terms episteme (knowledge) and logos (theory), and
accordingly this branch of philosophy is also referred to as the theory of
It is the branch of
philosophy that investigates the basic nature of knowledge, including its
sources and validation. Epistemology is concerned with the basic relationship
between man’s mind and reality, and with the basic operations of human reason.
It therefore sets the standards for the validation of all knowledge; it is the
fundamental arbiter of cognitive method.
a term in philosophy was probably first applied, by J. F. Ferrier, to
that department of thought whose subject matter is the nature and validity of
knowledge (Gr. epistimum, knowledge, and logos, theory, account;
Ger. Erkenntnistheorie). It is thus contrasted with metaphysics, which
considers the nature of reality, and with psychology, which deals with the
objective part of cognition, and, as Prof. James Ward said, "is
essentially genetic in its method." Epistemology is concerned rather with
the possibility of knowledge in the abstract. In the evolution of thought
epistemological inquiry succeeded the speculations of the early thinkers, who
concerned themselves primarily with attempts to explain existence. The
differences of opinion, which arose on this problem naturally, led to the
inquiry as to whether any universally valid statement was possible. The Sophists
and the Sceptics, Plato and Aristotle, the Stoics and the Epicureans took up
the question and from the time of Locke and Kant it has been prominent in
modern philosophy. It is extremely difficult, if not impossible, to draw a hard
and fast line between epistemology and other branches of philosophy. If, for
example, philosophy is divided into the theory of knowing and the theory of
being, it is impossible entirely to separate the latter (Ontology) from the
analysis of knowledge (Epistemology), so close is the connection 'between the
two. Again, the relation between logic in its widest sense and the theory of
knowledge is extremely close. Some thinkers have identified the two, while
others regard Epistemology as a subdivision of logic; others demarcate their
relative spheres by confining logic to the science of the laws of thought, i.e.,
to formal logic. An attempt has been made by some philosophers to substitute
"Gnosiology" for "Epistemology" as a special term for that
part of Epistemology which is confined to "systematic analysis of the
conceptions employed by ordinary and scientific thought in interpreting the
world, and including an investigation of the art of knowledge, or the nature of
knowledge as such." "Epistemology" would thus be reserved for
the broad questions of "the origin, nature and limits of knowledge".
The term Gnosiology has not come into general use.
issues have been discussed throughout the history of philosophy. Among the
ancient Greeks, questions of knowledge were raised by Plato and Aristotle, as
well as by the Sophists and the Sceptics, and many of the chief issues,
positions and arguments were explored at this time. In the systems of Plato and
Aristotle, however, epistemological questions were largely subordinated to
metaphysical ones, and epistemology did not emerge as a distinct area of
The scholastics of the
late medieval period were especially concerned with two epistemological
questions: the relationship between reason and faith, and the nature of
concepts and universals. The major positions on the latter issue—realism,
nominalism, and conceptualism—were defined during this period.
The Reformation and the
rise of modern science raised questions about cognitive methodology, and gave
rise to a rebirth of sceptical doctrines, trends that culminated in the
writings of Rene Descartes (1596-1650).
During the modern
period, from Descartes to Immanuel Kant (1724-1804), epistemological concerns
were at the forefront of philosophy, as thinkers attempted to understand the
implications of the new science. They also attempted, unsuccessfully, to deal
with sceptical attacks on the validity of sense perception, concepts, and
induction. In the 19th and 20th centuries, epistemological issues continued to
receive attention from philosophers of various schools, including Idealism,
Logical Positivism, and Linguistic Analysis.
A familiarity with the
history of philosophy provides the best introduction to epistemology. The
following works are of special importance for epistemology:
Locke, Essay Concerning Human Understanding
Kant, Prolegomena to Any Future Metaphysics
Epistemology as a discipline.
Why should there be such a subject as
epistemology? Aristotle provided the answer when he said that philosophy begins
in wonder, in a kind of puzzlement about things. Nearly all human beings wish
to comprehend the world they live in, a world that includes the individual as
well as other persons, and most people construct hypotheses of varying degrees
of sophistication to help them make sense of that world. No conjectures would
be necessary if the world were simple; but its features and events defy easy
explanation. The ordinary person is likely to give up somewhere in the process
of trying to develop a coherent account of things and to rest content with
whatever degree of understanding he has managed to achieve.
Philosophers, in contrast, are struck
by, even obsessed by, matters that are not immediately comprehensible.
Philosophers are, of course, ordinary persons in all respects except perhaps
one. They aim to construct theories about the world and its inhabitants that
are consistent, synoptic, true to the facts and that possess explanatory power.
They thus carry the process of inquiry further than people generally tend to
do, and this is what saying that they have developed a philosophy about these
matters means. Epistemologists, in particular, are philosophers whose theories
deal with puzzles about the nature, scope, and limits of human knowledge.
Like ordinary persons,
epistemologists usually start from the assumption that they have plenty of
knowledge about the world and its multifarious features. Yet, as they reflect
upon what is presumably known, epistemologists begin to discover that commonly
accepted convictions are less secure than originally assumed and that many of
man's firmest beliefs are dubious or possibly even chimerical. Anomalous
features of the world that most people notice but tend to minimise or ignore
cause such doubts and hesitations. Epistemologists notice these things too,
but, in wondering about them, they come to realise that they provide profound
challenges to the knowledge claims that most individuals blithely and
unreflectingly accept as true.
What then are these puzzling issues?
While there is a vast array of anomalies and perplexities, two of these issues
will be briefly described in order to illustrate why such difficulties call
into question common claims to have knowledge about the world.
TWO EPISTEMOLOGICAL PROBLEMS
"Our knowledge of the external world".
Most people have noticed
that vision can play tricks on them. A straight stick put in water looks bent
to them, but they know it is not; railroad tracks are seen to be converging in
the distance, yet one knows that they are not; the wheels of wagons on a movie
screen appear to be going backward, but one knows that they are not; and the
pages of English-language books reflected in mirrors cannot be read from left
to right, yet one knows that they were printed to be read that way. Each of
these phenomena is thus misleading in some way. If human beings were to accept
the world as being exactly as it looks, they would be mistaken about how things
really are. They would think the stick in water really to be bent, the railway
tracks really to be convergent, and the writing on pages really to be reversed.
These are visual anomalies, and they produce the sorts of epistemological
disquietudes referred to above. Though they may seem to the ordinary person to
be simple problems, not worth serious notice, for those who ponder them they
pose difficult questions. For instance, human beings claim to know that the
stick is not really bent and the tracks not really convergent. But how do they
know that these things are so?
Suppose one says that
this is known because, when the stick is removed from the water, one can see
that it is not bent. But does seeing a straight stick out of water provide a
good reason for thinking that it is not bent when seen in water? How does one
know that, when the stick is put into the water, it does not bend? Suppose one
says that the tracks do not really converge because the train passes over them
at that point. How does one know that the wheels on the train do not happen to
converge at that point? What justifies opposing some beliefs to others,
especially when all of them are based upon what is seen? One sees that the
stick in water is bent and also that the stick out of the water is not bent.
Why is the stick declared really to be straight; why in effect is priority
given to one perception over another?
One possible response to
these queries is that vision is not sufficient to give knowledge of how things
are. One needs to correct vision in some other way in order to arrive at the
judgement that the stick is really straight and not bent. Suppose a person
asserts that his reason for believing the stick in water is not bent is that he
can feel it with his hands to be straight when it is in the water. Feeling or
touching is a mode of sense perception, although different from vision. What,
however, justifies accepting one mode of perception as more accurate than
another? After all, there are good reasons for believing that the tactile sense
gives rise to misperception in just the way that vision does. If a person
chills one hand and warms the other, for example, and inserts both into a tub
of water having a uniform medium temperature, the same water will feel warm to
the cold hand and cold to the warm hand. Thus, the tactile sense cannot be
trusted either and surely cannot by itself be counted on to resolve these
Another possible response
is that no mode of perception is sufficient to guarantee that one can discover
how things are. Thus, it might be affirmed that one needs to correct all modes
of perception by some other form of awareness in order to arrive at the
judgement, say, that the stick is really straight. Perhaps that other way is
the use of reason. But why should reason be accepted as infallible? It also
suffers from various liabilities, such as forgetting, misestimating, or jumping
to conclusions. And why should one trust reason if its conclusions run counter
to those gained through perception, since it is obvious that much of what is
known about the world derives from perception?
Clearly there is a
network of difficulties here, and one will have to think hard in order to
arrive at a clear and defensible explanation of the apparently simple claim
that the stick is really straight. A person who accepts the challenge will, in
effect, be developing a theory for grappling with the famous problem called
"our knowledge of the external world." That problem turns on two
issues, namely, whether there is a reality that exists independently of the
individual's perception of it--in other words, if the evidence one has for the
existence of anything is what one perceives, how can one know that anything
exists unperceived?--and, second, how one can know what anything is really
like, if the perceptual evidence one has is conflicting.
The "other minds" problem."
The second problem also
involves seeing but in a somewhat unusual way. It deals with that which one
cannot see, namely the mind of another. Suppose a woman is scheduled to have an
operation on her right knee and her surgeon tells her that when she wakes up
she will feel a sharp pain in her knee. When she wakes up, she does feel the
pain the surgeon alluded to. He can hear her groaning and see certain
contortions on her face. But he cannot feel what she is feeling. There is thus
a sense in which he cannot know what she knows. What he claims to know, he
knows because of what others who have undergone operations tell him they have
experienced. But, unless he has had a similar operation, he cannot know what it
is that she feels.
Indeed, the situation is still more
complicated; for, even if the doctor has had such a surgical intervention, he
cannot know that what he is feeling after his operation is exactly the same
sensation that the woman is feeling. Because each person's sensation is
private, the surgeon cannot really know that what the woman is describing as a
pain and what he is describing as a pain are really the same thing. For all he
knows, she could be referring to a sensation that is wholly different from the
one to which he is alluding.
In short, though another
person can perceive the physical manifestations the woman exhibits, such as
facial grimaces and various sorts of behaviour, it seems that only she can have
knowledge of the contents of her mind. If this assessment of the situation is
correct, it follows that it is impossible for one person to know what is going
on in another person's mind. One can conjecture that a person is experiencing a
certain sensation, but one cannot, in a strict sense of the term, know it to be
If this analysis is correct, one can
conclude that each human being is inevitably and even in principle cut off from
having knowledge of the mind of another. Most people, conditioned by the great
advances of modern technology, believe that in principle there is nothing in
the world of fact about which science cannot obtain knowledge. But the "other-minds
problem" suggests the contrary--namely, that there is a whole domain of
private human experience that is resistant to any sort of external inquiry.
Thus, one is faced with a profound puzzle, one of whose implications is that
there can never be a science of the human mind.
These two problems resemble
each other in certain ways and differ in others, but both have important
implications for epistemology.
First, as the divergent
perceptions about the stick indicate, things cannot just be, as they appear to
be. People believe that the stick, which looks bent when it is in the water, is
really straight, and they also believe that the stick, which looks straight
when it is out of the water, is really straight. But, if the belief that the
stick in water is really straight is correct, then it follows that the
perception human beings have when they see the stick in water cannot be
correct. That particular perception is misleading with respect to the real
shape of the stick. Hence, one has to conclude that things are not always, as
they appear to be.
It is possible to derive
a similar conclusion with respect to the mind of another. A person can exhibit
all the signs of being in pain, but he may not be. He may be pretending. On the
basis of what can be observed, it cannot be known with certitude that he is or
that he is not in pain. The way he appears to be may be misleading with respect
to the way he actually is. Once again vision can be misleading.
Both problems thus force
one to distinguish between the way things appear and the way they really are.
This is the famous philosophical distinction between appearance and reality.
But, once that distinction is drawn, profound difficulties arise about how to
distinguish reality from mere appearance. As will be shown, innumerable
theories have been presented by philosophers attempting to answer this question
since time immemorial.
Second, there is the
question of what is meant by "knowledge." People claim to know that
the stick is really straight even when it is half-submerged in water. But, as
indicated earlier, if this claim is correct, then knowledge cannot simply be
identical with perception. For whatever theory about the nature of knowledge
one develops, the theory cannot have as a consequence that knowing something to
be the case can sometimes be mistaken or misleading.
Third, even if knowledge
is not simply to be identified with perception, there nevertheless must be some
important relationship between knowledge and perception. After all, how could
one know that the stick is really straight unless under some conditions it
looked straight? And sometimes a person who is in pain exhibits that pain by
his behaviour; thus there are conditions that genuinely involve the behaviour
of pain. But what are those conditions? It seems evident that the knowledge
that a stick is straight or that one is in great pain must come from what is
seen in certain circumstances: perception must somehow be a fundamental element
in the knowledge human beings have. It is evident that one needs a theory to
explain what the relationship is--and a theory of this sort, as the history of
the subject all too well indicates, is extraordinarily difficult to develop.
The two problems also
differ in certain respects. The problem of man's knowledge of the external
world raises a unique difficulty that some of the best philosophical minds of
the 20th century (among them, Bertrand Russell, H.H. Price, C.D. Broad, and
G.E. Moore) spent their careers trying to solve. The perplexity arises with
respect to the status of the entity one sees when one sees a bent stick in
water. In such a case, there exists an entity--a bent stick in water--that one
perceives and that appears to be exactly where the genuinely straight stick is.
But clearly it cannot be; for the entity that exists exactly where the straight
stick is is the stick itself, an entity that is not bent. Thus, the question
arises as to what kind of a thing this bent-stick-in-water is and where it
The responses to these
questions have been innumerable, and nearly all of them raise further
difficulties. Some theorists have denied that what one sees in such a case is
an existent entity at all but have found it difficult to explain why one seems
to see such an entity. Still others have suggested that the image seen in such
a case is in one's mind and not really in space. But then what is it for
something to be in one's mind, where in the mind is it, and why, if it is in
the mind, does it appear to be "out there," in space where the stick
is? And above all, how does one decide these questions? The various questions
posed above only suggest the vast network of difficulties, and in order to
straighten out its tangles it becomes indispensable to develop theories.
In accordance with a proposal made above,
epistemology, or the logic of scientific discovery, -should be
identified with the theory of scientific method. The theory of method, in so
far as it goes beyond the purely logical analysis of the relations between
scientific statements, is concerned with the choice of methods—with
decisions about the way in which scientific statements are to be dealt with.
These decisions will of course depend in their turn upon the aim, which we
choose from among a number of possible aims.
Methodology or a scientific
method is a collective term denoting the various processes by the aid
of which the sciences are built up. In a wide sense, any mode of investigation
by which scientific or other impartial and systematic knowledge is acquired is
called a scientific method.
What are the rules of
scientific method, and why do we need them? Can there be a theory of such
rules, a methodology? The way in which one answers these questions will largely
depend upon one’s attitude to science. The way in which one answers these
questions will largely depend upon one's attitude to science. Those who, like
the positivists, see empirical science as a system of statements, which satisfy
certain logical criteria, such as meaningfulness or verifiability, will
give one-answer. A very different answer will be given by those who tend to see
the distinguishing characteristic of empirical statements in their
susceptibility to revision—in the fact that they can be criticised,-and
superseded by better ones; and who regard it as their task to analyse the
characteristic ability of science to advance, and the characteristic manner in
which a choice is made, in crucial cases, between conflicting systems of
Such methods, as it was
mentioned above, are of two principal types— technical and logical.
A technical or technological method is a method of manipulating the
phenomena under investigation, measuring them with precision, and determining
the conditions under which they occur, so as to be able to observe them in a
favourable and fruitful manner. A logical method is a method of
reasoning about the phenomena investigated, a method of drawing inferences
from the conditions under which they occur, so as to interpret them as
accurately as possible. The term "scientific method" in the first
instance probably suggests to most minds the technical methods of manipulation
and measurement. These technical methods are very numerous and they are
different in the different sciences. Few men ever master the technical
methods of more than one science or one group of closely connected sciences. An
account of the most important technical methods is usually given in connection
with the several sciences. It would be impossible, even if it were desirable,
to give a useful survey of all, or even of the most important, technical
methods of science. It is different with the logical methods of science. These
methods of reasoning from the available evidence are not really numerous, and
are essentially the same in all the sciences. It is both possible and desirable
to survey them in outline. Moreover, these logical methods of science are in a
very real sense the soul of the technical methods.
In pure science the technical methods
are not regarded as an end in themselves, but merely as a means to the
discovery of the nature of the phenomena under investigation. This is done by
drawing conclusions from the observations and experiments, which the technical
methods render possible. Sometimes the technical methods make it possible for
the expert investigator to observe and measure certain phenomena, which
otherwise could either not be observed and measured at all, or not so
accurately. Sometimes they enable him so to determine the conditions of their
occurrence that he can draw reliable conclusions about them, instead of having
to be content with unverified conjectures. The highly speculative, mainly
conjectural character of early science was no doubt due entirely to the lack of
suitable technical methods and scientific instruments. In a sense; therefore,
it may be said that the technical methods of science are auxiliary to the
logical methods, or methods of reasoning. And it is these methods that are to
be considered in the present article. The technical methods of science, as
ought to be clear from the preceding remarks, are of first rate importance,
'and we have not the remotest desire to underrate them; but it would be futile
to attempt to survey them here.
Some Mental Activities
Common to All Methods.
There are certain mental
activities, which are so absolutely indispensable to science that they are
practically always employed in scientific investigations, however much these
may vary in other respects. In a wide sense these mental activities might consequently
be called methods of science, and they are frequently so called. But this
practice is objectionable, because it leads to cross division and confusion.
What is common to all methods should not itself be called a method, for it only
encourages the effacing of important differences; and when there are many such
factors common to all the methods, or most of them, confusion is inevitable.
When the mental activities involved are more or less common to the methods,
these must be differentiated by reference to other, variable factors—such as
the different types of data from which the inferences are drawn, and the
different types of order sought or discovered in the different kinds, of
phenomena investigated— the two sets of differences being, of course, intimately
connected. The mental activities referred to are the following: Observation
(including experiment), analysis and synthesis, imagination, supposition and
idealisation, inference (inductive and deductive), and comparison (including
analogy). A few words must be said about each of these; but no significance
should be attached to the order in which they are dealt with.
Observation and Experiment.
Observation is the act
of apprehending things and events, their attributes and their concrete
relationships. From the point of view of scientific interest two types of
observation may be distinguished, namely: (1) The bare observation of
phenomena under conditions which are beyond the control of the investigator,
and (2) experiment, that is, the observation of phenomena under
conditions controlled by the investigator. What distinguishes experiment from
bare observation is control over what is observed, not the use of
scientific apparatus, nor the amount of trouble taken. The mere use of
telescopes or microscopes, etc., even the selection of specially suitable times
and places of observation, does not constitute an experiment, if there is no
control over the phenomenon observed. On the other hand, where there is such
control, there is experiment, even if next to no apparatus be used, and the
amount of trouble involved be negligible. The making of experiments usually
demands the employment of technical methods, but the main interest centres in
the observations made possible thereby. The great advantage of experiment over
bare observation is that it renders possible a more reliable analysis of
complex phenomena, and more reliable inferences about their connections, by the
variation of circumstances, which it effects. Its importance is so great that
people commonly speak of "experimental method." The objection to this
is that experiment may be, and is, used in connection with various methods,
which are differentiated on other, and more legitimate, grounds. To speak of a
method of observation is even less permissible, seeing that no method can be
employed without it.
Analysis and Synthesis.
The phenomena of nature
are very complex and, to all appearances, very confused. The discovery of any
kind of order in them is only rendered possible by processes of analysis and
synthesis. These are as essential to all scientific investigation as is
observation itself. The process of analysis is helped by the comparison of two
or more objects or events that are similar in some respects and different in
others. But while comparison is a necessary instrument of analysis, analysis,
in its turn, renders possible more exact comparison. After analysing some
complex whole into its parts or aspects, we may tentatively connect one of
these with another in order to discover a law of connection, or we may, in
imagination, combine again some of them and so form an idea of what may be
common to many objects or events, or to whole classes of them. Some
combinations so obtained may not correspond to anything that has ever been
observed. In this way analysis and synthesis, even though they are merely
mental in the first instance, prepare the way for experiment, for discovery and
Such order as may be
inherent in the phenomena of nature is not obvious on the face of them. It has
to be sought out by an active interrogation of nature. The interrogation takes
the form of making tentative suppositions, with the aid of imagination, as to
what kind of order might prevail in the phenomena under investigation. Such
suppositions are usually known as hypotheses, and the formation of fruitful
hypotheses requires imagination and originality, as well as familiarity with
the facts investigated. Without the guidance of such hypotheses observation
itself would be barren in science for we should not know what to look for. Mere
staring at facts is not yet scientific observation of them. Hence for science
any hypothesis, provided it can be put to the test of observation or experiment,
is better than none. For observation not guided by ideas is blind, just as
ideas not tested by observations are empty. Hypotheses that can be put to the
test, even if they should turn out to be false, are called
"fruitful"; those that cannot be so tested even if they should
eventually be found to be true, are for the time being called
"barren." Intimately connected with the processes of imagination and
supposition is the process of idealisation, that is, the process of conceiving
the ideal form or ideal limit of something which may be observable but always
falls short, in its observed forms, of the ideal. The use of limiting cases in
mathematics, and of conceptions like those of an "economic man" in
science are examples of such idealisation.
This is the process of
forming judgements or opinions on the ground of other judgements or on the
evidence of observation. The evidence may be merely supposed for the sake of
argument, or with a view to the further consideration of the con-sequences, which
follow from it. It is not always easy to draw the line between direct
observation and inference. People, even trained people, do not always
realise, e.g., when they pass from the observation of a number of facts
to a generalisation which, at best, can only be regarded as an inference from
them. But the difficulty need not be exaggerated. There are two principal types
of inference, namely deductive and inductive. Inductive inference is the
process of inferring some kind of order among phenomena from observations made.
Deductive inference is the process of applying general truths or
concepts to suitable instances. In science inductive inference plays the most
important role, and the methods of sciences are mainly instruments of induction
or auxiliaries thereto. But deductive inference is also necessary to science,
and is, in fact, a part of nearly all complete inductive investigations. Still,
marked inductive ability is very rare. There are thousands who can more or less
correctly apply a discovery for one who can make it.
Comparison and Analogy.
Reference has already
been made to the importance of the process of comparison in the mental analysis
of observed phenomena. The observation of similarities and differences, aided
by the processes of analysis and synthesis, is one of the first steps to
knowledge of every kind, and continues to be indispensable to the pursuit of
science throughout its progress. But there are degrees of similarity. Things
may be so alike that they are at once treated as instances of the same kind or
class. And the formulation and application of generalisations of all kinds are
based upon this possibility of apprehending such class resemblances. On the
other hand, there is a likeness, which stops short of such close class
likeness. Such similarity is usually called analogy. The term is applied to
similarity of structure or of function or of relationship, in fact, to
similarity of almost every kind except that which characterises members of the
same class, in the strict sense of the term. And analogy plays very important
part in the work of science, especially in suggesting those suppositions or
hypotheses which, as already explained, are so essential to scientific research
After this brief survey of various
mental activities which are more or less involved in the pursuit of every kind
of knowledge, and consequently from no suitable bases for the differentiation
of the various methods of science, we may now proceed to the consideration of
the several scientific methods properly so called.
This may be described as
the oldest and simplest of scientific methods. The observation of similarities
between certain things, and classing them together, marks the earliest attempt
to discover some kind of order in the apparently chaotic jumble of things that
confront the human mind. Language bears witness to the vast number of
classifications made spontaneously by pre-scientific man. For every common noun
expresses the recognition of a class; and language is much older than science.
The first classifications subserved strictly practical purposes, and had
reference mainly to the uses which man could make of the things classified.
They were frequently also based on superficial resemblances, which veiled
deeper differences, or were influenced by superficial differences, which
diverted attention from deeper similarities. But with the growth of the
scientific spirit classifications became more objective or more natural,
attention being paid to the objective nature of the things themselves rather
than to their human uses. Even now scientific classification rarely begins at
the beginning, but sets out from current classifications embodied in language.
It has frequent occasion to correct popular classifications. At the same time
it has difficulties of its own, and more than one science has been held up for
centuries for want of a really satisfactory scheme or classification of the
phenomena constituting its field of investigation. To recognise a class is to
recognise the unity of essential attributes in a multiplicity of instances; it
is a recognition of the one in the many. To that extent it is a discovery of
order in things. And although it is the simplest method of science, and can be
applied before any other method, it is also the fundamental method, inasmuch as
its results are usually assumed when the other methods are applied. For
science is not, as a rule, concerned with individuals as such, but with kinds
or classes. This means that the investigator usually assumes the accuracy of
the classification of the phenomena, which he is studying. Of course, this
does not always turn out to be the case. And the final outcome of the
application of other methods of science to certain kinds of phenomena may be a
new classification of them.
Inductive and deductive
the summary of contrasts in the major tenets of inductivism and of Popper's
deductivism.. I begin with a caricature of inductivism in the form of
Science strives for justified, proven knowledge, for certain truth.
scientific inquiry begins with observations or experiments.
The observational or experimental data are organised into a hypothesis, which
is not yet proven (context of discovery).
observations or experiments are repeated many times.
The greater the number of successful repetitions, the higher the probability of
the truth of the hypothesis (context of justification).
As soon as we are satisfied that we have reached certainty in that manner we
lay the issue aside forever as a proven law of nature.
We then turn to the next observation or experiment with which we proceed in the
8. With the conjunction of
all these proven theories we build the edifice of justified and certain
the inductivist believes that science moves from the particulars to the general
and that the truth of the particular data is transmitted to the general theory.
will observe a caricature of Popper's theory of deduc-tivism, again in the form
of eight theses:
strives for absolute and objective truth, but it can never reach certainty.
scientific inquiry begins with a rich context of background knowledge and with
the problems within this context and with metaphysical research programmes.
theory, that is, a hypothetical answer to a problem, is freely invented within
the metaphysical research programme: it explains the observable by the
Experimentally testable consequences, daring consequences that is, are deduced
from the theory and corresponding experiments are carried out to test the
5. If an
experimental result comes out as predicted, it is taken as a value in itself
and as an encouragement to continue with the theory, but it is not taken as an
element of proof of the theory of the unobservable.
As soon as an experimental result comes out against the prediction and we arc
satisfied that it is not a blunder we decide to consider the theory falsified,
but only tentatively so.
concatenation of all these conjectures and refutations constitutes the dynamics
of scientific progress, moving ever closer to the truth, but never reaching
In summary, the
Popperian deductivist believes that science moves from the general to the
particulars and back to the general— a process without end. Let me inject a
metaphor. I might liken the Popperian view of science to that of a carriage
with two horses. The experimental horse is strong, but blind. The theoretical
horse can see, but it cannot pull. Only both together can bring the carriage
forward. And behind it leaves a track bearing witness to the incessant struggle
of trial and error.
Just as money makes
money, so knowledge already acquired facilitates the acquisition of more
knowledge. It is equally evident in the case of the method, which will now
engage our attention. The progress of science, and of knowledge generally, is
frequently facilitated by supplementing the simpler inductive methods by
deductive reasoning from knowledge already acquired. Such a combination of
deduction with induction, J. S. Mill called the "Deductive Method,"
by which he really meant the "Deductive Method of Induction." To
avoid the confusion of the "Deductive Method" with mere deduction,
which is only one part of the whole method, it is better to describe it as the
"Deductive-Inductive Method" or the "Inductive-Deductive
Method." Mill distinguished two principal forms of this method as applied
to the study of natural phenomena, -namely, (1) that form of it in which
deduction precedes induction, and (2) that in which induction precedes
deduction. The first of these (1) he called the "Physical Method";
the second (2) he called the "Historical Method."
These names are rather
misleading, inasmuch as both forms of the method are frequently employed in
physics, where sometimes, say in the study of light, mathematical (i.e.,
deductive) calculations precede and suggest physical experiments (i.e.,
induction), and sometimes the inductive results of observation or experiment
provide the occasion or stimulus for mathematical deductions. In any case, the
differences in order of sequence are of no great importance, and hardly deserve
separate names. What is of importance is to note the principal kinds of
occasion, which call for the use of this combined method. They are mainly three
in number: (1) When an hypothesis cannot be verified (i.e., tested)
directly, but only indirectly; (2) when it is possible to systematise a number
of already established inductions, or laws, under more comprehensive laws or
theories; (3) when, owing to the difficulties of certain problems, or on
account of the lack of sufficient and suitable instances of the phenomena under
investigation, it is considered desirable either to confirm an inductive
result by independent deductive reasoning from the nature of the case in the
light of previous knowledge, or to confirm a deductive conclusion by
independent inductive investigation.
An example of each of these
types may help to make them clear. (1) When Galileo was investigating the law
of the velocity of falling bodies he eventually formed the hypothesis that a
body starting from rest falls with a uniform acceleration, and that its
velocity varies with the time of its fall. But he could not devise any method
for the direct verification of this hypothesis. By mathematical deduction,
however, he arrived at the conclusion that a body falling according to his
hypothetical law would fall through a distance proportionate to the time of its
fall. This consequence could be tested by comparing the distances and the time of
falling bodies, which thus served as an indirect verification of his
hypothesis. (2) By inductions from numerous astronomical observations made by
Tycho Brahe and himself, Kepler discovered the three familiar laws called by
his name, namely, (a) that the planets move in elliptic orbits which have the
sun for one of their foci; (6) that the velocity of a planet is such that the
radius vector (i.e., an imaginary line joining the moving planet to the
sun) sweeps out equal areas in equal periods of time; and (c) that the squares
of the periodic times of any two planets (that is, the times which they take to
complete their revolutions round the sun) are proportional to the cubes of
their mean distances from the sun. These three laws appeared to be quite independent
of each other. But Newton systematised them all in the more comprehensive
induction, or theory, of celestial gravitation. He showed that they could all
be deduced from the one law that the planets tend to move towards each other
with a force varying directly with the product of their masses, and inversely
with the square of the distances between them. (3) H. Spencer, by comparing a
number of predominantly industrial States and also, of predominantly military
States, ancient and modern, inferred inductively that the former type of State
is democratic and gives rise to free institutions, whereas the latter type is
undemocratic and tends to oppression. As the sparse evidence hardly permitted
of a rigorous application of any of .the inductive methods, Spencer tried to
confirm his conclusion by deductive reasoning from the nature of the case in
the light of what is known about the human mind. He pointed out that in a type
of society, which is predominantly industrial, the trading relations between
individuals are the predominant relations, and these train them to humour and
consider others. The result is a democratic attitude in all. In a State, which
is predominantly military, the relations which are most common among its
members are those of authority, on the one part, and of subordination on the
other. The result is the reverse of a democratic atmosphere.
RELATION OF EPISTEMOLOGY TO OTHER BRANCHES OF PHILOSOPHY
In conclusion, I would like to
discuss the relation of epistemology to other branches of philosophy.
Philosophy viewed in the broadest possible terms divides into many branches:
metaphysics, ethics, aesthetics, logic, philosophy of language, philosophy of
mind, philosophy of science, and a gamut of others. Each of these disciplines
has its special subject matter: for metaphysics it is the ultimate nature of
the world; for ethics, the nature of the good life and how people ideally ought
to comport themselves in their relations with others; and for philosophy of
science, the methodology and results of scientific activity. Each of these
disciplines attempts to arrive at a systematic understanding of the issues that
arise in its particular domain. The word systematic is important in this
connection, referring, as explained earlier, to the construction of sets of
principles or theories that are broad-ranging, consistent, and rationally
defensible. In effect, such theories can be regarded as sets of complex claims
about the various matters that are under consideration.
Epistemology stands in a
close and special relationship to each of these disciplines. Though the various
divisions of philosophy differ in their subject matter and often in the
approaches taken by philosophers to their characteristic questions, they have
one feature in common: the desire to arrive at the truth about that with which
they are concerned--say, about the fundamental ingredients of the world or
about the nature of the good life for man. If no such claims were asserted,
there would be no need for epistemology. But, once theses have been advanced,
positions staked out, and theories proposed, the characteristic questions of
epistemology inexorably follow. How can one know that any such claim is true?
What is the evidence in favour of (or against) it? Can the claim be proven? Virtually
all of the branches of philosophy thus give rise to epistemological ponderings.
These ponderings may be
described as first-order queries. They in turn inevitably generate others that
are, as it were, second-order queries, and which are equally or more troubling.
What is it to know something? What counts as evidence for or against a
particular theory? What is meant by a proof? Or even, as the Greek Sceptics
asked, is human knowledge possible at all, or is human access to the world such
that no knowledge and no certitude about it is possible? The answers to these
second-order questions also require the construction of theories, and in this
respect epistemology is no different from the other branches of philosophy. One
can thus define or characterise epistemology as that branch of philosophy,
which is dedicated to the resolution of such first- and second-order queries.
1. A preface to the
logic of science, by Peter Alexander, Sheed and Ward, London and New York,
2. Popper selections,
by Dawid Miller, Princeton University press, 1985.
3. The critical
approach to science and philosophy, edited by Mario Bunge, The free press of
Glencoe Collier- Magmillan limited, London, 1964.
by Ernest Nagel, Glencoe, Ill..: Free
History of,", by D.W.
Encyclopaedia of Philosophy.
to Objectivist Epistemology, expanded 2nd
ed., by Ayn Rand, New
York: Penguin Group, 1990.