Anton Matyukhin

                                                              ICEF, GROUP 3,
                                                            ENGLISH GROUP 1.

                             ESSAY IN PHILOSOPHY


            Международный Институт Экономики и Финансов, 1 курс,
                           Высшая школа экономики.



1. Epistemology.
2. History.
3. Epistemology as a discipline
5. Implications.
6. Methodology.
7. Some Mental Activities Common to All Methods.
8. Observation and Experiment.
9. Analysis and Synthesis.
10. Imagination, Supposition and Idealisation.
11. Inference.
12. Comparison and Analogy.
13. Classification.
14. Inductive and deductive methods.
15. The Deductive-inductive Method.
17. Bibliography.


   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 knowledge.
   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
   Epistemology as 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.


Epistemological  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 inquiry.
   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:
Plato, Theaetetus
Aristotle, Posterior Analytics
Rene Descartes, Meditations
John Locke, Essay Concerning Human Understanding
David Hume, An Inquiry Concerning Human Understanding
Immanuel 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.

"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 difficulties.
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

 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 the case.
    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
   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
   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 exists.
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 theories.
   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

Imagination, Supposition and Idealisation.

   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 and discovery.
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

Inductive and deductive methods.

Below is 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 eight theses:
  1. Science strives for justified, proven knowledge, for certain truth.
  2. All scientific inquiry begins with observations or experiments.
  3. The observational or experimental data are organised into a hypothesis,
which is not yet proven (context of discovery).
  4. The observations or experiments are repeated many times.
  5. The greater the  number  of  successful  repetitions,  the  higher  the
probability of the truth of the hypothesis (context of justification).
  6. 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.
  7. We then turn to the  next  observation  or  experiment  with  which  we
proceed in the same manner.
8. With the conjunction of all these proven theories we  build  the  edifice
of justified and certain science.
   In  summary,  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.
   Now we will observe a caricature  of  Popper's  theory  of  deduc-tivism,
again in the form of eight theses:
1. Science strives for absolute and objective truth, but it can never  reach
2.  All  scientific  inquiry  begins  with  a  rich  context  of  background
knowledge and with the problems within this context  and  with  metaphysical
research programmes.
3. A theory, that  is,  a  hypothetical  answer  to  a  problem,  is  freely
invented  within  the  metaphysical  research  programme:  it  explains  the
observable by the unobservable.
4. Experimentally testable consequences, daring consequences  that  is,  are
deduced from the theory and corresponding experiments  are  carried  out  to
test the predictions.
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.
  6. 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.
  7. With this we gain a deeper understanding of our problem and proceed to
invent our next hypothetical theory for solving it, which we treat again  in
the same way.
8. The concatenation of all these conjectures  and  refutations  constitutes
the dynamics of scientific progress, moving ever closer to  the  truth,  but
never reaching certainty.
   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.

The Deductive-inductive Method.

   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
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.


   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, 1963.

2. Popper selections, edited by Dawid Miller, Princeton  University  press,

3. The critical approach to science and philosophy, edited by Mario  Bunge,
   The free press of Glencoe Collier- Magmillan limited, London, 1964.

4. Britannica encyclopaedia, 1948.

5. Logic without metaphysics, by Ernest Nagel, Glencoe, Ill..: Free  Press,

6. "Epistemology, History  of,",  by  D.W.  Hamlyn.  The  Encyclopaedia  of

7. Introduction to Objectivist Epistemology, expanded 2nd ed., by Ayn Rand,
   New York: Penguin Group, 1990.