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01 introduction

  1. What is philosophy? an introduction George Matthews Spring 2016
  2. What is philosophy?
  3. What is philosophy? Socrates c. 469 – 399 BCE The unexamined life is not worth living.
  4. What is philosophy? Socrates c. 469 – 399 BCE The unexamined life is not worth living. Socrates is often considered to be the father of Western philosophy. He spent his life encour- aging others to ask difficult questions about their values, assumptions and beliefs. He was executed for “corrupting the youth” by teaching them to ask similar questions.
  5. What is philosophy?
  6. What is philosophy? ! Philosophy is the attempt to understand the nature of reality and the significance of our lives based on the application of critical reasoning to our deepest and most general beliefs.
  7. What is philosophy? ! Philosophy is the attempt to understand the nature of reality and the significance of our lives based on the application of critical reasoning to our deepest and most general beliefs. ! Science tries to classify, explain and predict phenomena in the world.
  8. What is philosophy? ! Philosophy is the attempt to understand the nature of reality and the significance of our lives based on the application of critical reasoning to our deepest and most general beliefs. ! Science tries to classify, explain and predict phenomena in the world. ! Religion and the arts tell stories that provide meaning for human life in a larger context.
  9. What is philosophy? ! Philosophy is the attempt to understand the nature of reality and the significance of our lives based on the application of critical reasoning to our deepest and most general beliefs. ! Science tries to classify, explain and predict phenomena in the world. ! Religion and the arts tell stories that provide meaning for human life in a larger context. ! Philosophy seeks to identify, analyze and justify basic assumptions we make in hope of finding general truths about knowledge, reality and our social lives.
  10. What is philosophy?
  11. What is philosophy? ! Philosophy asks questions in a way that comes naturally to children – it is imaginative, born of wonder, and the mystery of life.
  12. What is philosophy? ! Philosophy asks questions in a way that comes naturally to children – it is imaginative, born of wonder, and the mystery of life. ! But it employs methods that come naturally to lawyers – it seeks to account for every last detail, employing analytical thinking, careful definitions and rigorous logic.
  13. philosophical questions
  14. philosophical questions Socrates c. 469 – 399 BCE How ought one to live one’s life?
  15. philosophical questions Socrates c. 469 – 399 BCE How ought one to live one’s life? NOTE:
  16. philosophical questions Socrates c. 469 – 399 BCE How ought one to live one’s life? NOTE: ! This is not a question about how we in fact live, but a question about how we should live.
  17. philosophical questions Socrates c. 469 – 399 BCE How ought one to live one’s life? NOTE: ! This is not a question about how we in fact live, but a question about how we should live. ! Such normative questions challenge us to give an account of ourselves, our values, our assumptions.
  18. philosophical questions Socrates c. 469 – 399 BCE How ought one to live one’s life? NOTE: ! This is not a question about how we in fact live, but a question about how we should live. ! Such normative questions challenge us to give an account of ourselves, our values, our assumptions. ! They encourage us to reflect on what we might normally take for granted in the attempt to justify our deepest beliefs.
  19. philosophical questions Socrates c. 469 – 399 BCE How ought one to live one’s life? NOTE: ! This is not a question about how we in fact live, but a question about how we should live. ! Such normative questions challenge us to give an account of ourselves, our values, our assumptions. ! They encourage us to reflect on what we might normally take for granted in the attempt to justify our deepest beliefs. ! Socrates’ question is a question in the sub-field of philosophy called “value theory” or “axiology.”
  20. philosophical questions Rene Descartes 1596 – 1650 What can I know with any degree of certainty?
  21. philosophical questions Rene Descartes 1596 – 1650 What can I know with any degree of certainty? NOTE:
  22. philosophical questions Rene Descartes 1596 – 1650 What can I know with any degree of certainty? NOTE: ! Descartes asked this question at the beginning of the scientific revolution, a time when old “certainties” were revealed to be little more than assumptions.
  23. philosophical questions Rene Descartes 1596 – 1650 What can I know with any degree of certainty? NOTE: ! Descartes asked this question at the beginning of the scientific revolution, a time when old “certainties” were revealed to be little more than assumptions. ! Answering it requires a clarification of what knowing in general involves as well as different types of knowledge.
  24. philosophical questions Rene Descartes 1596 – 1650 What can I know with any degree of certainty? NOTE: ! Descartes asked this question at the beginning of the scientific revolution, a time when old “certainties” were revealed to be little more than assumptions. ! Answering it requires a clarification of what knowing in general involves as well as different types of knowledge. ! Asking philosophical questions opens us up to the risk of not being sure how to answer them: do we really know anything at all with certainty?
  25. philosophical questions Rene Descartes 1596 – 1650 What can I know with any degree of certainty? NOTE: ! Descartes asked this question at the beginning of the scientific revolution, a time when old “certainties” were revealed to be little more than assumptions. ! Answering it requires a clarification of what knowing in general involves as well as different types of knowledge. ! Asking philosophical questions opens us up to the risk of not being sure how to answer them: do we really know anything at all with certainty? ! Descartes’ question is a question in the sub-field of philosophy called “epistemology” or “theory of knowledge.”
  26. philosophical questions Martin Heidegger 1889 – 1976 Why is there something rather than nothing?
  27. philosophical questions Martin Heidegger 1889 – 1976 Why is there something rather than nothing? NOTE:
  28. philosophical questions Martin Heidegger 1889 – 1976 Why is there something rather than nothing? NOTE: ! Philosophical questions are often much more general than questions we normally encounter.
  29. philosophical questions Martin Heidegger 1889 – 1976 Why is there something rather than nothing? NOTE: ! Philosophical questions are often much more general than questions we normally encounter. ! Science seeks answers to particular questions about how things work instead of such broad questions.
  30. philosophical questions Martin Heidegger 1889 – 1976 Why is there something rather than nothing? NOTE: ! Philosophical questions are often much more general than questions we normally encounter. ! Science seeks answers to particular questions about how things work instead of such broad questions. ! In Heidegger’s view philosophical questions may catch hold of us and refuse to let us go, even if we may not have a clear way of answering them.
  31. philosophical questions Martin Heidegger 1889 – 1976 Why is there something rather than nothing? NOTE: ! Philosophical questions are often much more general than questions we normally encounter. ! Science seeks answers to particular questions about how things work instead of such broad questions. ! In Heidegger’s view philosophical questions may catch hold of us and refuse to let us go, even if we may not have a clear way of answering them. ! Heidegger’s question is a question in the sub-field of philosophy called “metaphysics.”
  32. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  33. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  34. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  35. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  36. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  37. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  38. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  39. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  40. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  41. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  42. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  43. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  44. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  45. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  46. philosophy Metaphysics What kinds of things exist? How are mind and body related? Is there a God? Are we really free? Value Theory (axiology) Is beauty in the eye of the beholder? What would a just society look like? What is the right thing to do? Logic & Epistemology When is our reasoning reliable? What can we know? What is science and how does it work? a map of the territory
  47. the methods of philosophy
  48. the methods of philosophy
  49. the methods of philosophy ! Because philosophical questioning is open-ended and tries to get to the heart of things, how to do philosophy and whether we should bother are both open to question.
  50. the methods of philosophy ! Because philosophical questioning is open-ended and tries to get to the heart of things, how to do philosophy and whether we should bother are both open to question. ! In general though, philosophers proceed by:
  51. the methods of philosophy ! Because philosophical questioning is open-ended and tries to get to the heart of things, how to do philosophy and whether we should bother are both open to question. ! In general though, philosophers proceed by: Identifying assumptions, unquestioned beliefs, underlying pictures of how things are.
  52. the methods of philosophy ! Because philosophical questioning is open-ended and tries to get to the heart of things, how to do philosophy and whether we should bother are both open to question. ! In general though, philosophers proceed by: Identifying assumptions, unquestioned beliefs, underlying pictures of how things are. Developing arguments that might justify or refute these assumptions, beliefs and pictures.
  53. the methods of philosophy ! Because philosophical questioning is open-ended and tries to get to the heart of things, how to do philosophy and whether we should bother are both open to question. ! In general though, philosophers proceed by: Identifying assumptions, unquestioned beliefs, underlying pictures of how things are. Developing arguments that might justify or refute these assumptions, beliefs and pictures. Seeking clarification by making distinctions, defining terms, classifying positions.
  54. logic and the origins of philosophy Socrates c. 469 – 399 BCE
  55. logic and the origins of philosophy Socrates c. 469 – 399 BCE What is justice?
  56. logic and the origins of philosophy Socrates c. 469 – 399 BCE What is justice? Socrates was not the first person to ask such general questions. But he did notice how our answers to these questions are connected with many other beliefs, ideas and opinions we have. He paid attention to the logic of our beliefs.
  57. logic and the origins of philosophy Thrasymachus c. 459 – c. 400 BCE
  58. logic and the origins of philosophy Thrasymachus c. 459 – c. 400 BCE Justice is whatever the powerful say it is.
  59. logic and the origins of philosophy Thrasymachus c. 459 – c. 400 BCE Justice is whatever the powerful say it is. Thrasymachus was a “Sophist,” one of a group of professional teachers of rhetoric active dur- ing Socrates’ lifetime. The Sophists claimed to be able to convince anyone of anything and often scoffed at the idea of finding the real truth. Socrates considered them his enemies.
  60. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE
  61. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE Are you saying that might makes right?
  62. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE Yes I am.
  63. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE But isn’t it also true that even the powerful can make mistakes?
  64. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE Of course they can!
  65. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE But if they are mistaken, might what they do or demand go against their own interests?
  66. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE Yes . . .
  67. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE So they might act wrongly, even on their own terms, if they act based on their mistakes?
  68. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE I guess so . . .
  69. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE So there is a difference between being powerful and being right after all! And so might cannot make right.
  70. logic and the origins of philosophy Socrates c. 469 – 399 BCE Thrasymachus c. 459 – c. 400 BCE Shut up!
  71. logic and the origins of philosophy
  72. logic and the origins of philosophy ! Socrates insists on a clear statement of assumptions.
  73. logic and the origins of philosophy ! Socrates insists on a clear statement of assumptions. ! He draws out the implications of Thrasymachus’ definition.
  74. logic and the origins of philosophy ! Socrates insists on a clear statement of assumptions. ! He draws out the implications of Thrasymachus’ definition. ! He demonstrates that these implications are inconsistent with other beliefs that Thrasymachus holds.
  75. logic and the origins of philosophy ! Socrates insists on a clear statement of assumptions. ! He draws out the implications of Thrasymachus’ definition. ! He demonstrates that these implications are inconsistent with other beliefs that Thrasymachus holds. ! He is not after a rhetorical victory in a debate but is convinced that open discussion following the principles of logic will alone give us good reasons to believe what we believe.
  76. logic and the origins of philosophy ! Socrates insists on a clear statement of assumptions. ! He draws out the implications of Thrasymachus’ definition. ! He demonstrates that these implications are inconsistent with other beliefs that Thrasymachus holds. ! He is not after a rhetorical victory in a debate but is convinced that open discussion following the principles of logic will alone give us good reasons to believe what we believe. ! To find the truth we construct arguments in support of our claims and then critically analyze these arguments.
  77. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal.
  78. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. The premises are the statements we use to support our conclusion.
  79. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. The premises are the statements we use to support our conclusion. The conclusion is the claim we are attempting to establish with this argument.
  80. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. How can we tell whether an argument is any good?
  81. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. How can we tell whether an argument is any good? ! It must be valid: the conclusion must logically follow from the premises.
  82. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. How can we tell whether an argument is any good? ! It must be valid: the conclusion must logically follow from the premises. ! It must be sound: the premises must be true.
  83. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. How can we tell whether an argument is any good? ! It must be valid: the conclusion must logically follow from the premises. ! It must be sound: the premises must be true. To check for validity we ask, “Can these premises be true and this conclusion false at the same time?”
  84. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. If it is true that all humans are mortal . . .
  85. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. If it is true that all humans are mortal . . . and it is true that Socrates was a human . . .
  86. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. If it is true that all humans are mortal . . . and it is true that Socrates was a human . . . Then it seems clear that the conclusion must also be true.
  87. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. So this argument is VALID.
  88. logical analysis of arguments All humans are mortal. Socrates was a human. Thus Socrates was mortal. It is also SOUND since the premises are both true.
  89. logical analysis of arguments All humans are immortal. Socrates is a human. Thus Socrates is immortal.
  90. logical analysis of arguments All humans are immortal. Socrates is a human. Thus Socrates is immortal. ! This argument is also valid, even though one of the premises and conclusion are clearly false.
  91. logical analysis of arguments All humans are immortal. Socrates is a human. Thus Socrates is immortal. ! This argument is also valid, even though one of the premises and conclusion are clearly false. ! This is because IF the premises were true, the conclusion would also have to be true.
  92. logical analysis of arguments All humans are immortal. Socrates is a human. Thus Socrates is immortal. ! This argument is also valid, even though one of the premises and conclusion are clearly false. ! This is because IF the premises were true, the conclusion would also have to be true. This argument is thus VALID, but UNSOUND since the first premise is false.
  93. logical analysis of arguments All dogs are mammals. My brother is a mammal. Thus my brother is a dog.
  94. logical analysis of arguments All dogs are mammals. My brother is a mammal. Thus my brother is a dog. ! Suppose both of these premises were true.
  95. logical analysis of arguments All dogs are mammals. My brother is a mammal. Thus my brother is a dog. ! Suppose both of these premises were true. ! Does that mean that the conclusion also MUST be true?
  96. logical analysis of arguments All dogs are mammals. My brother is a mammal. Thus my brother is a dog. ! Suppose both of these premises were true. ! Does that mean that the conclusion also MUST be true? Clearly not! So this argument is INVALID, and because of this it is automatically UNSOUND.
  97. summary: argument analysis
  98. summary: argument analysis identify argument
  99. summary: argument analysis identify argument Is it valid?
  100. summary: argument analysis identify argument Is it valid? Can premises be true and conclusion false?
  101. summary: argument analysis identify argument Is it valid? Can premises be true and conclusion false? INVALID YES
  102. summary: argument analysis identify argument Is it valid? Can premises be true and conclusion false? INVALID VALID NO
  103. summary: argument analysis identify argument Is it valid? INVALID VALID Are premises true?
  104. summary: argument analysis identify argument Is it valid? INVALID VALID Are premises true? no: UNSOUND discard
  105. summary: argument analysis identify argument Is it valid? INVALID VALID Are premises true? no: UNSOUND discard yes: SOUND accept
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