Epistemology: the study of the nature, source, limits,

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Epistemology the study of the nature, source,
limits, justification of knowledge

• Skepticism doubt that knowledge is possible

• Taoism the differentiation of things is
  relative all things are really one

• Pyrrhonism we should refuse to make
  dogmatic claims to know because all
  knowledge is relative

Chuang Tzu (369-286 BCE)
Sextus Empiricus (2nd Century)
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Cartesian Doubt

• Sense experiences are often wrong
• I might be wrong about whether I have a body or
  if there is a world apart from my imagination (it
  may be a dream)
• I might be wrong even about whether my reasoning
  abilities (e.g., 235) can be trusted (evil
  genius) so I should suspend judgment

René Descartes (1596-1650)
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Objections to Descartes Method of Doubt

• To think some experiences are wrong is to assume
  that some are right
• To doubt everything, we must doubt whether we are
  truly doubting, and that requires us to assume a
  public world of language users
• Limiting knowledge only to what we know with
  certainty is too restrictive we often know
  things not based on indubitable foundations

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Hume Skepticism about the External World

• The continued existence of things apart from our
  experience cannot be known, for we cannot compare
  our experience (or self) with anything outside it
  as its supposed cause
• Problem of induction we cannot say that
  something is probable without assuming that the
  future will resemble the past
• Induction itself is unjustifiable (Strawson)