Introduction to PhilosophyLecture 1-a

What is philosophy?

By David Kelsey

What is philosophy?

• The word Philosophy:– Philo-:– sophy:

• Philosophy is the systematic investigation into the foundational concepts and principles of any subject matter.

– A subject matter is:

Explaining a subject matter

• So philosophy consists of the investigation of any subject matter.

• Understanding and Explaining a subject matter

• Example: Epistemology and knowledge

The disciplines of philosophy

• The disciplines of philosophy include:

– Philosophy of religion:

– Philosophy of mind:

– Ethics:

– Metaphysics:

– Others…

The tasks of philosophy

• A philosopher investigates the concepts and principles of any subject matter by use of:

– Conceptual analysis & Argumentation

• Conceptual analysis is the analysis of concepts.– Concepts:

• 2 definitions: words vs. ideas about a bit of the universe

• Examples:

The extensions of concepts

• Concepts have extensions:– For something to be in the extension of (or to fall under) a

concept: • the thing must be an instance of the concept.• The thing must fall under the concept

– If X is in the extension of a concept then…

– Example:• Knowledge

– The extension of any concept: defined as a set of things…

A view on Concepts

– A view on concepts: You might also think that concepts are abstract objects which are instantiated in our world.

– The picture:– LOVE KNOWLEDGE STUDENT – PHILOSOPHY SCHOOL– WORD TRUTH GRADE– --------------------------------------------------------------------------------------------------– L W P K T Sc G St – W L P K T Sc St G– L P W K T Sc G St

– Above the line: abstract objects– Below the line: our world.

– Where do concepts lie?– Where is a concept instantiated, above or below the line?– The extension of a concept is:

Conceptual analysis

• If you will remember, one of the main tasks of philosophy is the analysis of concepts.

• To analyze a concept is – An explanation

– A definition

• To define a concept:– Examples in the dictionary

• The philosopher’s task:– To provide more detailed, full and clear explanations of concepts you can find in your

what?

Analytical Definitions: their form

• An Analytical definition is composed of a definiendum and a definiens.– The definiendum:

– The definiens:

• Form: the form of a definition is this:– X =df _____

• Which is the definiendum and which is the definiens?

– For example,

• Bachelor =df unmarried adult male

Necessary andsufficient conditions

• We can think of a definition as a set of necessary and sufficient conditions.

• X is a necessary condition of Y if and only if (or iff) we cannot have Y without also having X.

– Oxygen and Combustion

• X is a sufficient condition of Y iff X is all that is needed to get Y.– Being born in the US and citizenship

Necessary and Sufficient Conditions #2

• X is both a necessary and sufficient condition of Y iff both – 1) we cannot have Y without also having X &

– 2) X is all that is needed to get Y.

• Bachelorhood and being an unmarried adult male

The Goal of Philosophy: FindingCorrect Definitions

• For a definition to be adequate the definiendum and definiens must be co-extensive.

• For the defiendum and definiens of any definition to be co-extensive it must be the case that:

– Everything in the extension of the definiendum is in the extension of the definiens and vice versa…

Co-extensiveness:An example

• So if your definition of BACHELOR as UNMARRIED ADULT MALE is correct then:

– Everything in the extension of BACHELOR is in the extension of UNMARRIED ADULT MALE and vice versa.

Testing definitions

• To determine if a definition is adequate:– determine if its definiendum and definiens are co-extensive.

– Is there any item in the extension of one that isn’t in the extension of the other?

• Example: Car =df 4 wheeled vehicle one can drive– All Cars are 4 wheeled vehicles one can drive.

– All 4 wheeled vehicles one can drive are Cars.

• Universal generalizations and counterexamples– A counterexample: a case that violates a universal generalization.

Counterexamples

• 2 examples:• Defining Car as 4 wheeled vehicle one can drive:

– We need to find either a Car that isn’t a 4 wheeled vehicle one can drive

– Or a 4 wheeled vehicle one can drive that isn’t a Car

– Thoughts?

• Defining Knowledge as true belief:– We need to find either

– a case of knowledge that isn’t what?

– Or a case of true belief that isn’t what?

– A counterexample:• The Belief Game:

Counterexamples #2

• Love: Say I define Love as a deep seated feeling composed of compassion & care which one can have for another human being.

– Can anyone find a counterexample to this definition?

• We are looking for either:– a case of love that isn’t ____________

– a case of having this feeling for another human which isn’t ______________

– Any thoughts?