Empiricsm

POS

Scientific Knowledge

According to Charles Pierce, a pragmatist philosopher, there are four important sources of knowledge viz.

Authority

Tenacity

Scientific Knowledge

Pierce further suggests that scientific knowledge has evolved as the most practical and significant form of knowledge. Even though like other forms of knowledge, scientific knowledge has its own limitations as well. Nevertheless, it draws its practical significance and universal applicability owing to the epistemological presuppositions that explain the basis for the sources and validation of scientific knowledge.

To understand the true nature of scientific knowledge it is essential to understand the epistemological underpinnings of scientific knowledge. To comprehend the epistemological presuppositions of scientific knowledge it is better to start with an understanding of two philosophical perspectives on sources of knowledge viz. Empiricism and Rationalism. However, before that, we take up the matter of defining knowledge. 

Knoweldge:

The term knowledge has a very common and widespread usage both in the academic as well as a non-academic arena. At the same time, the concept eludes any particular definitional boundary. 

The most talked-about and still the most accepted view on knowledge is that of the JTB theory or the tripartite theory of knowledge that imposes three conditions for qualification of a proposition as knowledge. The three conditions are:

a. There is a knower S who has a belief in proposition P.

b. The proposition P is true. Thus there is a correspondence between reality and what the statement P entails.

c. S has a justification to believe P to be true.

The third condition i.e the justification condition is a matter of debate and often conflicting views have been put forth regarding the nature of the justification for considering a belief P in science as true. Justification for belief in the truth of P presents the grounds or the evidential reasons that a knower S presents to establish P as truth.

There have been two theories of justification for the knowledge presented by the philosophers in form of empiricism and rationalism. Both theories have profoundly influenced our conception of the nature of scientific knowledge.

Empiricism

There are two schools of philosophers with regard to the question on the source of scientific knowledge viz. Empiricist School and Rationalist school. Hume, Berkeley, Locke, Mill etc. all belong to the Empiricist school of philosophers. 

• Scientific knowledge has it's source in sensory perception

To the question regarding the source of knowledge, the empiricists' thinkers like John Locke, George Berkeley and David Hume, consider the sensory perception or experiences as the ultimate source of knowledge and hence scientific knowledge is to be validated against the sensory perceptions.

According to Velasquez (2007), Empiricism is the philosophical position that holds the belief that "all knowledge about the world comes from or is based on the senses" (p.207). The human mind, when a child is born is like a clean slate (tabula rosa) and then it is through different sensory interactions with the world that experiences are created and imprinted on the mind. This was the basic position held by the empiricist John Locke. 

Berkely believed that all knowledge has its source in the perception of a conscious mind. Nothing can be real or can be claimed as knowledge if it is not perceived by a conscious mind. This he asserts that one can apply the principle of esse est percipi which means "to be is to be perceived".

For Hume, all contents in the mind can be ultimate regressed to or reduced to "those given by senses or experience" (Velasquez, 2007:213). What the senses give to our mind was termed by him as the perception. The perception was classified as an impression when the knower directly senses the objects in a vivid way. When the knower reflects or thinks over some impression it leads to the formation of ideas. Thus every idea in the mind ultimately has a sensory perception or impression at its root. According to Hume, there can be no valid knowledge without any corresponding sensory impression. 

• Science deals with a-posteriori knowledge

Since all knowledge has its source in sensory experiences, it is believed that all true knowledge can arise only after experience or post-experience. Hence the empiricist claim that all true knowledge is a-posteriori (Post experience). No knowledge can exist devoid of any sensory experience associated with it. 

• Science implies teastability and verifiability

Since all knowledge has its source in sensory perception, the knowledge can be verified and tested. Thus true knowledge is one that is verifiable and testable. Thus verification and testability become a standard for judging the validity of knowledge. This belief in the verifiability of knowledge is often referred to as Verificationism. 

Thus, in a nutshell, the empiricist presents justification in form of sensory impression or perception and it is through the sensory impression or the potential sensory impression that validity of knowledge could be determined.

Reflection

Is there any element of a prior knowledge in science?

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