Nature of Science:

1. Empiricism (Aristotle, Locke, Berkeley, Hume) Observation & experience ;Rejects, priori reasoning
2. Logical Positivism (Vienna Circle) Confirmation of scientific theory by induction/deduction
3. Karl Popper’s falsification-All theories should have the nature of falsification.
4. Lakatos ‘research programs’;An alternative theory of paradigm
5. Fayerabend’s theory of Anarchistic history;Based on humanitarian ground, doesn’t believe in paradigm or standard methods.
6. The Bayesian approach;Confirmation of new scientific knowledge influenced by previous success probabilities

Empiricism:

The initial thought in the philosophy of science was mostly dominated by the concept of empiricism. The empiricism emphasizes those aspects of scientific knowledge that are closely related to evidence, especially as discovered in experiments (Chalmers, 1999). The idea of empiricism is that the science is to be based on what we can see, hear and touch rather than on personal opinions or speculative imaginations. Based on Aristotelian theory of tabula rosa, which state that the human mind is like a blank table and that their knowledge comes from experience and perception. Empiricism is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world, rather than resting solely on a priori reasoning, intuition, or revelation. Therefore, empiricist claims that the science is methodologically empirical in nature. Some of the classical empiricists were John Locke, George Berkeley, and David Hume (Godfrey-Smith, 2003).

Logical Positivism:

It is a school of philosophy that combines empiricism with rationalism incorporating mathematical logics known as deductions in epistemology.Logical positivism has advocated the observation based theory should be tested through experiments. One drawback of logical positivism is the logical induction. Logical positivism has put forward the concept of generalization through induction. This suggests that the appropriate facts can be established in science by large number of observations under a wide variety of conditions, and there should not be any conflict with the derived law (Chalmers, 1999). It means replication of experiments many times to make it a standard theory.

Karl Popper’s falsification:

Karl popper was sharply against the idea of logical positivism or induction for generalization of the theory. Therefore, Poo\pper formulated his demarcation criterion for distinguishing science from non-science, where the criterion pertains to falsifiability. The falsificationist sees science as a set of hypothesis that is tentatively proposed with the aim of accurately describing or accounting for the behavior of some aspect of the world or universe. There is one fundamental condition that any hypothesis or system of hypothesis must satisfy if it is to be granted the status of scientific law or theory, a hypothesis must be falsifiable.

Kuhn’s Paradigm:

Inductivist and falsificationist accounts of science were challenged in a major way by Thoman Kuhn. He came to believe that traditional accounts of science, whether inductivist or falsificaniost, do not bear comparison with historical evidence. Kuhn’s account of science was subsequently developed as an attempt to give a theory more in keeping with the historical situation as he saw it. A key feature of his theory is the emphasis placed on the revolutionary character of scientific progress, where revolution involves the abandonment of one theoretical structure and its replacement by another, incompatible one (Godfrey-Smith, 2003).

Lakatos ‘research programs’:

Lakatos like Kuhn, saw the merit in portraying scientific activity as taking place in a framework, and coined the phrase “research program”. According to Lakatos some laws or principles are more basic than others and that can be the defining feature of a science. A science can then be seen as the programmatic development of the implications of the fundamental principles.

Fayerabend’s theory of Anarchistic history:

Fayerabend from his humanitarian point of view supports his anarchistic theory of science on grounds that it increases the freedom of scientists by removing them from methodological constraints and, more generally, leaves individuals the freedom to choose between science and other forms of knowledge. A central problem with Feyerabend’s notion of freedom stems from the degree to which it is entirely negative, in the sense that freedom is understood as freedom from constraints.

The Bayesian approach:

Bayes’ theorem is about conditional probabilities, probabilities for propositions that depend on the evidence bearing on those propositions. Those probabilities will be subject to change by the punter in the light of new evidence. Bayes’ theorem is a theorem prescribing how probabilities are to be changed in the light of new evidence.