Epistemology is the study that focuses our means to acquire knowledge, cultivates the way we think and the way we differentiate between true and false. Epistemology can be defined as – ‘the investigation into the grounds and nature of knowledge itself'.
Empiricism is the substantial part of Epistemology though there are some people (rationalists) who believe that senses might mislead us towards acquiring knowledge. For example, in desert our eyes tell us that there is water on the road. The theory of empiricism deals with the way we gain knowledge. The word ‘Empiricism’ is educed from the Greek word eµpe???sµ??, in Latin which is experiential and from experiential the word ‘experience’ is derived. Empiricism also derives from the word empiric – a doctor who relies on practical experience and rejects attachment to the dogmatic doctrines [2, 3]. Most of the advocates of empiricists recognize the existence of some priori truths like those of mathematics and logic. 
Columbia Encyclopedia has defined ’empiricism’ as a ‘philosophical doctrine that all knowledge is derived from experience’ . Again, according to Geography Dictionary, empiricism is ‘the theory that all concepts emanate from experience and that all statements claiming to express knowledge must be based on experience rather that on theory’ .
So, after analyzing the definitions from different sources it can be easily pronounced that empiricism is the doctrine which says knowledge comes from our experience, either sensed via the five senses (sight, hearing, touch, smell and taste) or via our mind.
When someone throws a ball into the air and watches it to fall, he/she feel confirm that the ball will fall down as it obey the law of gravity. But how do people know it? May be seeing it occur myriad times, or from understanding some bedrocks of the universe. Empiricists are the people who believe the first proposition.
Empiricists think that principles or ideas can be derived wholly from experiment and all knowledge of matters ultimately derives from and must be tested by experience . He does not concentrate on theory rather on observation and experiment. He emphasizes inductive method of reasoning, observes the objective of facts and claims that ‘no one could have knowledge of the world unless he had experience’ .
Though Aristotle (384-322 BC) had some important rationalistic elements in his philosophy, sometimes he is called the founder of the tradition of empiricism . While talking about empiricists we find another important name Epicurus (341-270 BC), whose work (Epicureanism) was also based on acquiring knowledge from senses . Besides, John Locke (1632-1704) and George Berkeley (1685-1753) are the two renowned British empiricists.
What I should have said is that my experiences have weakened, not my belief that there is no life after death, but my inflexible attitude towards that belief.
– Alfred Jules Ayer in his article “What I saw when I was dead” 
Logical Empiricism is also known as logical positivism or neo positivism. The mastermind of logical empiricism was the Vienna Circle, a group of philosophers in early 20th century. The rising period of logical empiricism is the early 20th century, when Gottlob Frege (1848-1925) and Ludwiq Wittgenstein (1889-1951) attempted to combine the substantive theme of British empiricism with some under standing of mathematical logic [2, 5 and 6].
According to Stanford Encyclopedia of Philosophy, “Logical positivism is a school of philosophy that combinesempiricism- the idea that observational evidence is indispensable for knowledge of the world – with a version ofrationalismincorporating mathematical and logico-linguistic constructs and deductions inepistemology” [7, 8]. Though logical empiricism strongly influenced the development of analytic philosophy after World War II period and spread out in Europe and America in the mid 20th century, its influence declined during mid 1960s [7, 8]. How ever, Karl Popper (1902-1994), Alfred Jules Ayer (1910-1989) and Hilary Putnam (1926- ) were the well known critics of this philosophical concept [9, 10 and 11].
The only principle that does not inhibit progress is: anything goes.
-Paul K. Feyerabend
Paul K. Feyerabend has talked a lot about the problems of contemporary empiricisms as well as about the ‘Logical Empiricists’. He also criticized Nagel’s Formal Model of Intertheoretic Reduction in his paper, “How to Be a Good Empiricist – A Plea for Tolerance in Matters Epistemological”. If we look at the track of Paul K. Feyerabend’s life, who was born on January 13, 1924, in Vienna, we can see that he had close relationships with the big three philosophers in the arena of philosophy of science in the second half of the 20th century – Popper (in 1950s), Kuhn (in early 1960s) and Lakatos (in 1960s and 70s) .
Feyerabend believed Modern empiricism is very different from the empiricism of Galileo, Faraday and Einstein. He addressed ‘Logical empiricists’ as the enemies of the progress of science. In early ages these people were just priests or ‘school philosophers’, but within few decades they have named themselves as the ‘philosopher of science’ . These people are grievous than the earlier because they deceive their followers by taking the epithet of ‘progressivism’ and ’empiricism’. Feyerabend said, one can be a good empiricist only if he is prepared to work with many alternative theories rather than with a single standpoint and experience . ‘Alternative theories must be developed in such detail that problems already solved by an accepted theory can again be treated in a new and perhaps also more detailed manner’. Definitely such evolution is time consuming .
One of the cornerstones of contemporary empiricism is its ‘Theory of Explanation’ . ‘Theory of Explanation’ is an elaboration of some simple ideas first proposed by Karl Popper, who was not interested about when a theory can be said to be true or accepted. Rather he was more concerned on distinguishing science from non-science or pseudoscience. And he reckoned this is the central question in the philosophy of science. Popper was interested on Marx’s theory of history, Freud’s psycho-analysis and Alfred Adler’s Individual Psychology. But he was mostly interested by Albert Einstein’s Theory of Relativity . Popper did not like the classical demarcation criterion. He thought Pseudoscience is as derogatory as Metaphysics. Popper constituted the concept of falsifiability, which later on became an important concept in the field of science and philosophy of science.
‘Theory of Explanation’ can be explained in this way: Let T and T’ are two scientific theories. T’ is the theory to be explained (reduced theory). T is the explaining theory (reducing theory). D’ is the domain inside which T’ is applicable. Now ‘Theory of Explanation’ implies two things :
I. Consequences of a satisfactory explaining theory (T) inside D’, must be compatible with the theory to be explained (T’).
II. Main descriptive terms of the consequences of T must either coincide with the main descriptive terms of T’, or at least they must be related to them via an empirical hypothesis. Means that, the meaning of T’ must be unaffected by the explanation.
These two conditions are as Feyerabend said – ‘I shall call the consistency condition and the Condition of meaning invariance’. He also named them as ‘Conditions of Contemporary Empiricism’ .
It is obtrusive that notation and explanation of Feyerabend is just opposite of Nagel. For Ernest Nagel T’ reduces or in a sense explains T. So, for Nagel, T’ is the reducing theory and T is the reduced theory.
Feyerabend thought both ‘Consistency condition’ and ‘Condition of Meaning Invariance’ restrain the emergence of knowledge. Feyerabend showed that the development of actual science does not always follow these two conditions, rather they have violated often.
It is well known that Newton’s theory is inconsistent with Galileo’s law of the free fall and with Kepler’s laws of planetary motion. There are also many more similar examples of inconsistency between laws (e.g. inconsistency between wave optics and geometrical optics). But interesting thing is – inconsistency does not reside between Newton’s theory and Galileo’s law, rather ‘some consequences of Newton’s theory in the domain of validity of Galileo’s law, and Galileo’s law’ is inconsistent .
According to Galileo’s law ‘acceleration of the free fall is a constant’ . But application of Newton’s theory to the surface of the earth states that, acceleration is not constant rather it decreases with the increment of distance from the center of the earth. This inconsistency is quite logical, as it is too minor to notice by experimentation. Here Feyerabend posited in this way – ‘If actual scientific procedure is to be the measure of method, then the consistency condition is inadequate’ .
While talking about ‘Meaning Invariance’, Feyerabend used the concept of classical conservation of mass and Einstein’s special relativity.
According to ‘Classical Conservation of Mass’, in a closed system S, if m1,m2,m3,â€¦.mn are the masses of the parts p1,p2,p3,â€¦pn, then the mass of an aggregate of parts equals to the sum of the masses of the parts. It can be shown by the following notation-
M (S Pn) = S M (Pn)
But according to Einstein’s special relativity mass of an object depends upon its velocity (m = m0/v (1 – v^2/c^2)). It means ‘the relative velocities and the relative potential energies contribute to the mass balance’ .
So, by focusing the meanings of the terms used in the relativistic law and in the corresponding classical law, Feyerabend claimed that the concept of mass from relativistic point of view and from classical point of view is quite different, as in the case of relativistic concept mass is a relation involving relative velocities between an object and a coordinate system, but for classical concept mass is just a property of the object itself and quite autonomous of its behavior in coordinate systems . So ‘mass conservation cannot be explained in terms of relativity without a violation of meaning invariance’ . In this perspective Feyerabend stated that, “the meaning of every term we use depends upon the theoretical context in which it occurs” !
A person who never made a mistake never tried anything new.
Feyerabend thought modern empiricism is walking in a wrong direction and then he prefers a different approach of empiricism, which he called ‘Good Empiricism’. Refusing the concepts of contemporary empiricisms Feyerabend prescribed some criteria about good practice of empiricism and way to be a good empiricist. Feyerabend said – ‘A good empiricist will not rest content with the theory that is in the center of attention and with those tests of the theory which can be carried out in a direct manner’ . He will pursue to invent alternatives, which will be used to produce criticism those are most fundamental. It means he will always appreciate the plurality of theories as well as admonish dogmatism. At first he will try to formulate some general suppositions. Those suppositions are not directly linked with observations. This step can be named as ‘the invention of a new metaphysics’ . So a good empiricist must also be a good metaphysician .
“Fear God and he will give you knowledge”
After spilling a lot of words about the doctrine of empiricism now I am going to write something of my very own and it is about acquisition of knowledge.
When a baby is born his experience about the world outside of the mama’s womb is considered quite null. Gradually he started knowing and growing. Knowing mainly from experiences. At a time human being starts to take decision based on his acquired knowledge. But if it is said that human being takes all of his decisions from experience and observation, then it will an act of totally ignoring the words ‘logical thinking’ and ‘common sense’, as I think it grows inside the human being intuitively. But I think logical deduction of a fact covers an important part of our knowledgebase.
I think that the word ‘faith’ is not in the dictionary of an empiricist, particularly spiritual belief. Because, the empiricist only believes the thing he has observed or experienced. Personally I am a believer. Though throughout my life so far I have never faced a single angel or daemon or have not got any chance to talk to them. I think each and every person has some philosophy of his own. I am not a blink believer of God, as I have some reason derived by my intellectuality which has made me satisfied. From my childhood I have been taught about different activities and practices of the religion, but that didn’t make me a believer. I have noticed that the holy book and the holy prophet of my religion had never been acquainted a single word that is harmful for me, that will make my life awful or even something illogical. So, now if my friend (here, the holy prophet and the holy book) says thousands of true sentences to me, then I merely believe one more sentence of him, ‘Your god is one god; there is no god but He, Most Gracious, Most Merciful’! Whatever, this discussion might not seem interesting to some of my readers, so let’s talk something about the observation of Aristotle.
According to the observation of Aristotle, planet earth is in the center of the universe and everything including the sun is moving around it. Everything was fine with this concept and with the support of Bible it resides in the world of science for more then two thousand years, until the tremendous invention of Tycho Brahe, Galileo, Newton and Copernicus. So, it is easy to say that though people believed what Aristotle said, the universe was acting on its true way and eventually the sun did not move around earth for those days.
So, our eyes might see something wrong and it might always not be the same what we see, like water place in the desert due to mirage!
So, it is necessary to count both empiricism with logical deduction and justification while acquiring knowledge, as it is a continuous process throughout the lifespan. Being only empiricist it is not possible to conclude solution to all the problems and incidents, problems like the origin of universe or what happen after death or even different sides of human mind!
“I think and think for months and years. Ninety-nine times, theconclusionis false. The hundredth time I am right.” –Albert Einstein
I think experience and sensory perception, which is the base of the doctrine of empiricism, is not the only way we acquire knowledge. In born human being have some innate ideas that help him to take decision. However, by something ‘innate’ I do not mean that an infant knows something about God or logical analysis or may be about language and expression. Rather, I think innate knowledge is something that deviate one man from another. For example we can assume that if two babies (who are twine) are kept in two identical environment, and it is assumed that both of them will have the same food, same education, ultimately everything same! And when they grow up, if they are given a problem to solve, there is definitely a big chance that they will solve the problem in two different ways, if there are multiple options (or, they will express different opinion about a fact)! This is the thing that makes two person’s point of observation different. Precisely empiricism is threatened by the concept of Thought Experiment. Galileo, Newton and Einstein are the good examples of expert of thought experiment. There is no strong evidence that Galileo climbed up the leaning tower of Pisa to make an experiment of his law of free fall. Even it is well known that Newton’s famous story about sitting under an apple tree is just a myth! So, when thought experiment is affording a lot to the mine of science, it would be interesting to see how empiricism confronts it.
Besides, I think knowledge acquired from induction (inducing a decision about a thing based on the experiment on a small part of it) is occupying an important part of our knowledgebase, whose contribution is undeniable.
I am very worried when professional illusionists are being paid a good amount of money to deceive our eyes and senses, how the can empiricists can just rely on it (observation, sense)! So I think observed data should be rational and a good philosopher should neither be an orthodox empiricist nor rationalist but a mixture of both. Otherwise, in future we will have to experience more something like Aristotle’s concept of motionless earth revolved by the sun, based on observation. Then we will again need one Copernicus, to develop the true mathematical model of the system.
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