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
  posteriorii.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.