# All knowledge claims should be open to rational criticism. On what grounds and to what extent would you agree with this assertion?

Rational Criticism in Knowledge Claims

#6: All knowledge claims should be open to rational criticism. On what grounds and to what extent would you agree with this assertion?

Henry Deng

IB Candidate Number:

Theory of Knowledge

International Baccalaureate Programme

Sir Winston Churchill Secondary School

Ms. Patton

16 April 2009

Henry Deng

Ms. Patton

IB TOK 11

16 April 2009

Criticism, as proposed by Karl Popper, is “the lifeblood of all rational thought.” At a first glance, one may agree with this because by critically questioning or evaluating the validity of a knowledge claim through reason, it can provide one with certainty and truth. However, the assertion that: “All knowledge claims should be open to rational criticism” gives us an alternative judgement as the word “should” is not definitive and this perhaps suggests that it is necessary to consider other viewpoints. Through inductive and deductive reasoning, we can test knowledge claims and indicate the grounds of which the claim is based on. Yet, as evidenced by Victor Johnson’s hedonic tone theory and the notion of altruism, emotion plays an important role in our reasoning process which asks the question of whether rational criticism is free of these emotional motives. In mathematics, people tend to accept knowledge claims like: the sum of a triangle’s internal angles is equal to 180 degrees, without a rational basis. A growing number of people believe that the arts are subjective or based on personal taste because of its abstract nature, which may suggest that these knowledge claims are not open to rational criticism in the first place. Although we can examine various knowledge claims using inductive and deductive reasoning, this process might not be applicable to all areas of knowledge.

For most, certainty is possible in rudimentary arithmetic as few doubt that 1 + 1 = 2; although this claim can be rationally criticized, many of us do not question its validity because the definition of two is two ones. This possibility of certainty, however, does not apply to all areas of mathematics, especially in complex theorems that need to be vigorously tested before publication. Although mathematics may require the use of various syllogisms like logic, the validity of deductive reasoning is based upon the logic of the argument and not the truth of its foundation. This truth is assumed to be correct: for mathematics, however, this truth is compulsory in order for us to continue with the deductive process. Kurt Gödel, a prominent mathematician, proposes that “it is impossible to prove the consistency of arithmetic, which is to say, [there is] no rigorous proof that the basic axioms of arithmetic do not lead to a contradiction at some point.” (“Is Arithmetic Consistent?”) So, when different branches of mathematics are used in order to prove something more abstract such as modelling real life phenomena, there exists difficulty in detecting which claims are made from falsely assumed truths or contradictions. One can find truth in mathematics using deductive reasoning; however, this truth may or may not be properly proved.