Logical Positivism Flashcards
What are the three central ideas of logical positivism? Briefly explain them.
1) Analytic vs synthetic distinction
-Analytic Statements: True by virtue of their meaning (“All triangles have 3 sides”) you know it’s true, independent of any experiment
-Synthetic Statements: True by virtue of reality (“Chris is a bachelor”) requires some investigation
2) Principle of verification
-A sentence is meaningful iff it can be verified or tested by experience/observation
-Science contains all cases of knowledge, everything else (except math and logic) is meaningless.
3) Observational and Theoretical language
-Observational Statements: connect us to reality/external world, capture the content of sense experience (Basic Statements)
-“I saw a chair in the room”
-Particular claims about the content of one’s immediate experience (observational statements)
-Theoretical Statements: No clear connection to immediate observation, are treated as “hypotheses” which we are justified in believing only on the basis of the evidence provided by the “observation statements.”
-“All atoms have electrons”
-Universal claims about the world (theoretical statement)
Given the principle of verifiability, what is science?
-Science is meaningful non science is meaningless
-A sentence is meaningful iff it can be verified or tested by experience/observation
-Science contains all cases of knowledge, everything else (except math and logic) is meaningless.
-Principle of verification solved the problem of demarcation (what is or is not science)
Briefly explain the Hypothetico-deductive view on the relationship between observational and theoretical statements. Explain it.
-Get inspiration from observation, form hypothesis: all swans are white
-See what prediction comes from hypothesis: (next swan will be white)
-If true, theory confirmed
-Science starts at Observational (particular) Statements > Theoretical (universal) Statements
-Observational: Counting Swans; swan 1 is white, swan 2 is white, swan 3 is white (particular)
-Theoretical: “All swans are white” (universal)
When does a particular observation confirm a universal theory?
-Step 1: Context of discovery- come up with a hypothesis
-Step 2: Context of justification- set a procedure to justify/evaluate your hypothesis, set hypothesis, draw a prediction, test prediction, if it passes, it’s confirmed
-Formulate hypothesis, test on observable data
-Prediction: next swan you will observe is going to be white
-If true, increases the probability of hypothesis, confirms theory
Use an example to explain Hempel’s paradox of confirmation.
Problem:
T1) All ravens are black
T2) All non black things are non ravens
-Logically equivalent, contraposition
-Therefore, whatever confirms the first confirms the second, and vice versa
-T1 all ravens are black things
-Find ravens, see what colors they are
-Case1 the raven is black
-Probability raised
-Case2 the raven is black
-Probability raised
-Case 1 and 2 confirm theory
-T2 All non black things are non ravens- Anything that confirms this theory confirms first theory
-Look at something non black
-Look at white swan, is non raven
-Probability raised, Confirms T2
-Look at pink pencil, is non raven
-Probability raised, Confirms T2
-Look at green grass, is non raven
-Probability raised, Confirms T2
-If T2 is confirmed, T1 is confirmed
-Pink pencil, green grass, white swan, can confirm all ravens black
-Don’t even need to leave the room to confirm theory
Use an example to explain Goodman’s paradox of induction.
-All grasses are green
-Look at grass to see if it’s green
-Green grasses confirms theory
-New color, glue, green up to 2030, then turns blue
-How do you know the grass is green and not glue?
-You can’t know
