1. What is Scientific Knowledge?

2. What is “knowledge”? 1. A person must hold a belief. 2. This belief must be true. 3. There must be evidence that the belief is true. Knowledge = “justified true belief” Do YOU believe that humans can influence global warming? Or do YOU know this on the basis of evidence and reason?

3. Problems with “absolute truth” Plato’s allegory of the cave All truth-claims can be unpicked All swans are white (on this pond, today) 1 + 1 = 2 (in decimal but not binary)

4. Richard Dawkins Professor of the Public Understanding of Science Oxford University “There are two ways of looking at the world. Through faith and superstition, or through the rigors of logic, observation and evidence, through reason” ( Dawkins) But is it possible to distinguish between scientific (rational) knowledge and “mere” (irrational?) belief?

5. Auguste Comte (1796-1857) Only our sensory experience gives us “positive” (measurable) knowledge of reality… The goal of scientific knowledge is merely to describe the phenomena experienced (not question their existence). 1. Describing what we observe (Positivism)

6. Our (sensory) experiences must be formulated into hypotheses (or predictions) which can be tested to determine their truth (verified). Kepler (1571-1630) did not “see” eliptical orbits but worked them out logically 2. Describing AND making predictions (Logical Positivism)

7. If we cannot prove things are true, then how can we distinguish knowledge from “mere” belief? David Hume (1711- 1776) showed that there is no justification for believing that which we have experienced will be the same as that which we have yet to experience (principle of induction)

8. Karl Popper (1902-1994) Falsificationism It is the scientific method that guarantees the “objectivity” of scientific knowledge. 3. Describing AND making predictions using knowledge that is open to falsification (Critical rationalism)

9. If it is irrational to accept truth claims this means it is also irrational to accept as conclusive the (truth) claim that a particular theory is false. This ‘falsificationist’ credo leads to the inevitable conclusion that we can never find out what is true. Indeed we cannot even know what is ‘truly’ false. But if we do not know what is true OR false, then how can knowledge grow?

10. “Conjectures & refutations” New conjectures (opinions without proof) confront selective pressures, they meet the competition of alternative theories, critical arguments and experimental testing, and only the ‘fittest’ (given the empirical tools and understandings of the time) ‘survive.’

11. Popper imposes one set of rules (the logic of falsification applied to conjectures), against which all systems of thought are to be judged.

12. Objective knowledgeOther knowledge Can be falsified by the scientific method “science” Cannot be falsified by the scientific method “non-science” e.g. physics e.g. astrology, religion, etc.

13. Problem: We have to set up tests according to agreed criteria (rules) Are black swans “real” swans? The truth or falsity of any scientific test can only be evaluated in terms of beliefs, values, standards and methods and aims of its practitioners (the agreed rules).

14. 4. Scientific knowledge, like “other” knowledge is grounded in sets of rules made by the scientific community. These rules enable certain findings to be legitimate while excluding others. There is no overarching theoretical framework that can adjudicate between competing conceptual schemes. Scientific knowledge is therefore RELATIVE (not priviledged or “more true” than other knowledge)

15. Either there is a fixed foundation for knowledge, or we cannot escape the forces of darkness that envelop us with madness, with intellectual and moral chaos (Bernstein 1983) The relativist view is HIGHLY PROBLEMATIC

16. We have separated knowledge into a rational/scientific variety (knowledge) and an irrational/other variety (belief, relativism). We need to invent another way of thinking which puts the two back together again. Knowledge and belief are NOT polar opposites. It here that a “postmodern” way of thinking which could be called a “logic of uncertainty,” begins to make sense.