Popper On Science

1. Popper On Science Economics 201 - Lawlor

2. What is and inductive inference? • Example: “All Swans are white” • Needs an observation to confirm it’s truth. • It is impossible to think of a logical deductive proof, one that proceeds from a general principle to a single instance • The next observation could always contradict it. • Economics Example: “Returns to holding equities are the highest of all classes of investment”

3. Problem with induction (pp. 27-30 • According to Hume and Popper • The is no “logical” way to define an inference • Must always be open to disproof • Is always tentatively held • Could be disproved by the next observation

4. Four Aspect of Theory Testing (p. 32) • 1.Internal Consistency – math, logic • 2. Deductive Determination of Testable Hypotheses • 3. Comparison with other theories – to eliminate special cases, more generality, etc.. • 4. Empirical Testing of conclusions derived in #2

5. “Demarcation” of Empirical Science (pp. 34-36) • A method of distinguishing what is and is not empirical science • First, why do we need one • To be clear about the problem discussed by Ludwig Wittgenstein: Can the problem of “universal statements” about “reality” be reduced to a logical relationship • Logical Positivists and early Wittgenstein said “yes,” “meaningfulness” and the “picture theory”

6. Popper and Hume’s reply...(pp. 36-8 • If, with Hume, we recognize the difference of empirical and a priori statements, and if we recognize that only a prior truth is established by deduction… • Then statements that depend on empirical verification can never be proven true by deduction • Must always remain inductively “tentative”

7. “Falsifiability” (pp. 40-41) • A method, or “convention”, of presenting an inductive, empirical statement, in such a way as to ensure it is scientific, not metaphysical (in the sense of not being determined by evidence) • Read quote p. 40-1, “But I shall…” • “it must be possible for an empirical statement to be refuted by experience”

8. Status of “Falsification” (pp. 41-42) • Is itself a not provable by deduction • We must judge by experience if it is useful to wisely apply it when conducting science • Asks: “Is science better off accepting as proof ‘evidence’ or ‘belief’”? • When and whether it is the former over the latter is Popper’s point: Scientific progress is made when more evidence is explained

9. Range of empirical “falsifiability is a mark of its generality • “Not for nothing do we call the laws of nature ‘laws’: the more they prohibit the more they say” (p. 41) • Consider the “law of gravity” – what sort of things does it prohibit? • Consider “the law of diminishing returns” in the same light • “prohibits” much less

10. Scientific Objectivity and Subjective Conviction (pp. 44-48) • Belief and Faith have no role in an empirical science unless it is faith in evidence • Evidence as judged by the weight of evidence by a wide community is Popper’s ideal currency to a scientific community • He is calling us to be true empiricists – to live without conviction, tentatively, based on evidence

11. Science and Metaphysics • Any belief we consider too precious to be open to “falsification,” is a metaphysical belief for Popper • It is difficult to live without “belief” psychologically – so it is difficult to be a true empirical scientist • But such is the ideal science • And also his description of how science progresses • Note not by “ideology” but by “facts”

12. Note that this was not just philosophy for Popper • Jewish refugee from Vienna, 1932 • Author of The Open Society and Its Enemies • He personally lived through the domination of German public discourse by the Nazi ideology, and suffered from it • Proposed that public debate, to guard against this, be based on “facts,” not “belief”