Philosophy of Science

1. Philosophy of Science Science is the study of alternative explanations. What is an explanation?

2. Explanation • An explanation is an answer to the question, “Why does that happen?” • An explanation is also called a “theory.” • It consists of statements from which one can deduce the phenomena to be explained. • It must satisfy several criteria

3. Criteria for Explanation • Deductive • Meaningful • Predictive • Causal • General

4. Before we can understand the Criteria of Explanation, we need to understand types of statements.

5. Types of Statements • Definitions= statements of equivalence in language. • Logical Statements= a priori true or false, based on logical analysis. • Empirical= statements whose truth is tested a posteriori—i.e., by observations of the “real world.”

6. Definition A Definition is a statement of equivalence. For example, “A Bachelor is defined as a human male who has never been married.” A definition is neither true nor false. However, it would be confusing to use terms differently from that given by convention (dictionary).

7. Operational Definition • An Operational Definition is a definition that specifies the operations of measurement. • For example, operational definitions of “male” might be based on external genitalia, chromosomes, hormones, internal organs, birth certificate, gender identity, sexual orientation, clothes, etc.

8. Logical Statements A logical statement is one whose truth is tested by logical analysis. A logical statement is a priori true or a priori false. For example, “Some bachelors are married” is a priori false. We do not need to conduct a survey of bachelors to know that this statement is false. All we need do is see that if a bachelor is never married then they cannot now be married. It contradicts the definition.

9. Logical Statements • The statement, “All bachelors are human” is a priori true, because the definition of bachelor is that a person is human and male and never married. • The term for “and” is conjunction. The symbol used in set theory is . We can write, bachelor  {human  male  never married}

10. Logical Statements • “Some Bachelors are Married” • This is a priori false. Do we need to do a survey? It contradicts the definition. • “Some Bachelors are female.” • This is a priori false, given the definition. • “Some Bachelors are human.” • A priori true, since all bachelors are human.

11. Empirical Statements • Empirical statements are statements whose truth is tested a posteriori. • They are statements about the “real world,” about observations we have made or can make. • For example, “Some bachelors are taller than 6 feet.” • This statement is a posteriori true, because we have measured the heights of human males who were never married and found some who were this tall.