What is science?
BY CARLO Fonseka
BY virtue of such training as I have had in biology and
medicine, my approach to science is essentially sociobiological.
Sociobiology is the exploration of the biological basis of social
behaviour and organization. I regard science as the embodiment of the
most reliable knowledge about the world humankind has hitherto acquired.
The term 'reliable knowledge' in the present context implies that it can
be trusted to produce expected results. In my field of supposed special
competence, it is now clichetic to say that at any given time, half of
what doctors know is wrong. If so, how reliable in fact is medical
knowledge? The history of medical knowledge is the history of painfully
groping towards higher degrees of reliability. As with medicine, so with
other sciences.
To talk of reliability is to raise another question.
Given that we find ourselves in this world not knowing whence we came
and why, what is our business on earth? Observation shows that willy
nilly, avoidance of suffering and pursuit of happiness are what people
are frequently engaged in, in their diverse ways. Biology teaches that
the brain is the organ that guides us in our endeavours to avoid
suffering and to pursue happiness.
Our endeavours succeed to the extent
that the judgements we make with our brains concerning the nature of the
world correspond to its real nature. Our judgments are based on our
perceptions which themselves depend on what the world appears to be to
our sense organs such as our eyes and ears.
But experience has shown us that appearances can be
deceptive. Hence the need for science. As Karl Marx memorably said: "All
science would be superfluous if the outward appearance and the essence
of things directly coincided".
Because of the fallibility of our senses, our judgments
based on our perceptions must be justified by the exercise of our
critical intelligence. When so viewed, science comes to consist of
judgments about the world based on perceptions and justified by reason.
This implies that science is knowledge; that is to say
an understanding of some aspect of the nature of the world based on
accurate information. Therefore to say what science is, it is necessary
to discuss the problem of knowledge.
In the last analysis, the problem of knowledge boils
down to finding an answer to a specific question. The question is this:
What are the necessary and sufficient conditions that must be fulfilled
for one to claim that one truly knows that something is really the case?
As lucidly, expounded by A.J. Ayer in his book called -
'The Problem of Knowledge' (1956), three conditions must be fulfilled
before one can claim to really know that a proposition is true.
First: What one is said to know must be true.
Second: One must be sure it is true.
Third: One must have the right to be sure that it is
true.
Suppose, for example, I claim that I know there is a
mango tree in your garden. What are the necessary and sufficient
conditions that must be fulfilled for my claim to acquire the status of
a definite item of knowledge?
First, there really must be a mango tree in your garden.
But that is not enough by itself to validate my claim that I have
definite knowledge of its existence. A second condition must be
satisfied before my claim can aspire towards the status of knowledge. If
I had just guessed that there is a mango tree in your garden and my
guess happened to be correct, I cannot validly claim that I knew that it
was there.
For me to claim that I have knowledge, I must be sure on the
basis of some evidence such as having seen it one or more times that
there is in fact a mango tree in your garden. Even my subjective
certainty based on my observation, however, is not sufficient to make my
claim to knowledge a valid one. Why not? Because my sureness may be
based on circumstances that do not entitle me to be sure. Given that
humans are not only prone to err, but are also liable to be victims of
illusions, hallucinations and delusions, my subjective certainty may be
based on uncheckable, unverifiable evidence.
Therefore it is necessary
for a third condition to be satisfied before my claim to knowledge
becomes a valid one. Not only must what I claim to know be true; I must
also be sure that it is true; and, most importantly, I must have the
right to be sure that it is true.
The rights to be sure is earned in various ways. In the
hard sciences, an essential part of the validation of a claim to
knowledge is that the evidence on which such a claim to knowledge is
based should be capable of being publicly checked. Why? Because what is
not publicly checkable may become a matter of disagreement and whenever
there is unsettlable disagreement we reach a dead end.
Objection
A valid objection to this approach to knowledge would be
that the criterion of truth employed is majoritarianism. That is to say,
the idea that what is rationally verifiable should be verifiable to the
satisfaction of the competent, orthodox majority.
The fact is that all
major advances in science have been instances in which the traditional
orthodox majoritarian view has been proved wrong or has been
substantially revised. So much so that the modern scientific tradition
has been characterized as the tradition of questioning tradition.
"The important thing" Albert Einstein once said, "is not
to stop questioning". Awareness of the reality that the validity of
scientific knowledge is not absolutely certain induces in scientists an
appreciation of the value of a healthy dose of rational doubt (as
opposed to philosophical skepticism, which altogether denies the very
possibility of knowledge).
Such rational doubt is the necessary corrective to
current certainties which constitute the basis of our everyday working
hypotheses. By its very nature, science is obliged to confine itself to
empirical problems (in contrast to metaphysical ones) which can be
formulated as testable hypotheses.
In philosophical terms, science is concerned with
synthetic propositions i.e. with knowledge based on experience.
So it includes all statements of particular facts e.g.
grass is green, and all generalizations which are not logically
necessary e.g. all men are mortal. Science is not directly concerned
with analytic propositions such "2 and 2 are 4" or "a triangle has three
angles" which are true by definition. Mathematics and deductive logic
consist of analytic propositions.
Verification and refutation
When a strictly scientific approach is deployed to
investigate a given phenomenon, the brain uses three processes, namely,
careful observation, logical reasoning and rigorous testing. The
conclusions arrived at by this technique have a high degree of
predictive value.
That is to say, they enable us to confidently expect
such and such results, when such and such actions are performed. Indeed,
the final test of the validity of a scientific hypothesis is to see
whether predictions from it come true. If predictions from a hypothesis
do not match observed facts, then the hypothesis fails the test; that
is, it is refuted.
Therefore the process of testing a scientific hypothesis
is simultaneously an attempt at refuting it (falsification) or
confirming it (verification). The significance of refuting a hypothesis
is quite different from the significance of confirming it. Refuting a
hypothesis in respect of a major aspect of it kills it; but even
repeated confirmation does not make it immortal.
To cite the stock example: based on millions of
observations Europeans had formulated the hypothesis that "all swans are
white". When they discovered black swans in Australia the hypothesis was
refuted and invalidated.
In scientific terms, refuting a hypothesis invalidates
it; confirming it by means of particular instances does not and
logically cannot make it universally valid. Why not? Because according
to current probability theory, the probability of a universal statement
being true is zero, whatever the observational evidence.
Thus refutation of a hypothesis is conclusive;
confirmation does not make it absolutely certain. Hence absolute
certainty is unattainable by scientific method.
Therefore scientific knowledge formulated in the form of
theories or hypotheses - must remain permanently doubtful.
Even so, when wisely used, they have proved to be
sufficiently reliable for the purpose of reducing avoidable human
suffering and promoting human welfare. This does not apply to knowledge
of particular facts e.g. that boiling water is hotter than ice is
absolutely certain.
A theory
In contrast to a hypothesis, a theory is a set of ideas
or concepts that is intended to explain some natural phenomenon. A
theory that survives has gone through three stages. In the first stage,
it is a matter of controversy among people who have studied it
carefully.
In the second stage, there is consensus among the
specialists who have studied it, that the theory is the one which best
fits the relevant facts, even though the fit may not be perfect. In the
third stage, it is tacitly assumed by all that any new evidence will
require only revision, amendment or modification of the theory and not
total rejection.
A theory may survive in this stage for decades or even
centuries. If new evidence creates too many problems for the theory,
however, a sort of intellectual revolution occurs in the scientific
community and a "paradigm shift" occurs.
This is the view that Thomas Kuhn advanced in his famous
book called 'The Structure of Scientific Revolutions' published in 1962.
The view that scientific method essentially involves or
should involve the attempt to falsify testable hypotheses is associated
with the name of Karl Popper. These two approaches to science are often
presented as polar opposites, but they don't have to be so regarded.
It is when some fundamental working hypothesis operating
within a given theoretical framework becomes completely falsified, that
a paradigm shift occurs. a theory is not discarded merely because some
observations are not compatible with it. It is discarded only when
another theory appears which can fit in more facts than the discarded
theory is capable of explaining.
That is how, for example, Einstein's theory of
gravitation replaced Newton's theory of gravitation. The practical
difference between the two theories is very small. Newton's theory of
gravitation is reliable enough to go to the moon. It is the theoretical
difference between the two theories that is very great. Einstein's
theory can explain everything that Newton's theory can-and more.
Nature of science
We are now sufficiently prepared to answer the question:
What is this thing called science? There are some who go so far as to
declare categorically that there is no single category called "science"
with valid evaluative criteria that can be applied to the study of such
diverse areas as physical, biological, mental, historical and social
phenomena.
They claim that each area has to be investigated in
terms of its own specified aims. to the extent that the method of
investigating a phenomenon uses careful observation, logical reasoning
and rigorous testing the knowledge so obtained would acquire a "law
like" character suffused with predictive value.
In proportion to the degree that a given investigation
falls short of the ideal specifications of careful observation, logical
reasoning and rigorous testing, its reliability as a guide to action is
compromised.
Science as a body of knowledge consists of the sum total
of tentative conclusions reached by using the technique of careful
observation, logical reasoning, and rigorous testing. It embodies
judgments about the world based on perception and justified by reason.
(Extracted from 'The Case for Socialism' (2004) edited
by Wesley S. Muthiah and Sydney Wanasinghe) |
