History of Philosophy Lecture 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: The concept knowledge picks out lots of things in the world… –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 then is just all of its instantiations.

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?

Definitions An Analytical definition is composed of a definiendum and a definiens. –The definiendum: what is to be defined –The definiens: what defines Form: the form of a definition is this: –X =df _____ Which is the definiendum and which is the definiens? –For example, Knowledge =df true belief

Necessary and sufficient 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. Example: knowledge as JTB

The goal of Philosophy: Finding Correct Definitions So one of the main tasks of Philosophy: is to define concepts. –Defining concepts: When defining philosophical concepts, we aren’t out to define them in any old way we like. –Adequate Definitions: We want to find the correct or adequate definitions of our philosophical concepts. –Co-extension: For a definition to be adequate the definiendum and definiens must be co-extensive.

Co-extensiveness 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: –1) –2) –What is the extension of a concept? Example in knowledge as JTB…

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: Knowledge is true belief All Knowledge is true belief. All true belief is knowledge. Universal generalizations and counterexamples

Counterexamples: Knowledge A counterexample: a case that violates a universal generalization. If we define knowledge as true belief we just need one counterexample to show this definition inadequate. –We need to find a case of knowledge that isn’t what? –Or a case of true belief that isn’t what? –A counterexample: The Belief Game:

A counterexample to a definition of Love 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?