Epistemology

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Epistemology

• How do I know anything?

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Epistemology

• The branch of philosophy that studies the nature,
  sources, limitations, and validity of knowledge

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Rationalism

• This is the position that reason alone, without
  the aid of sensory information, is capable of
  arriving at some knowledge, at some truth
• Basic knowledge is arrived at by perception

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Perception

• This is the process of seeing, hearing, smelling,
  touching, and tasting through which we become
  aware of ordinary objects
• Rationalists believe that we can acquire accurate
  knowledge about the world simply by looking into
  our minds
• For the rationalist, knowledge is a priori that
  is, pertaining to knowledge that is logically
  prior to experience reasoning based on such
  knowledge

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The dilemma

• How can we know anything about the world without
  first observing it?
• Well, what about the mathematician?
• Many laws of nature have been established outside
  of sensory observation
• Math algebra, calculus, trigonometry
• Physics

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Remember

• Rationalists do not necessarily believe that
  knowledge is arrived at through reason alone.
• Knowledge can also be arrived at by sensory
  observation i.e. A giraffe has spots

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And then we have Descartes

• René Descartes was a rationalist to the extreme
• He believed that the mind is entirely separate
  from the body Cartesian Dualism
• Claimed that the senses cannot be trusted
• Asserted that our sense perceptions may be dreams
  or hallucinations

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Descartes

• According to Descartes, the senses distort our
  view of reality
• They are an unreliable knowledge source
• Descartes soon came to doubt everything that he
  could not prove to be certain
• The only certainty was that he existed
• The confirmation of this was I think, therefore,
  I am (Cogito ergo sum)

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Empiricism

• This is the position that knowledge has its
  origins and derives all of its content from
  experience
• This position is a reaction to rationalism
• Empiricists assert that knowledge is a posteriori
  that is, that knowledge pertains to that which
  is empirically verifiable inductive reasoning

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John Locke

• He claims that the mind is a blank slate on which
  experience makes its mark
• This is known as tabula rasa
• For Locke, all knowledge has its origins in sense
  experience

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The dilemma

• Can we trust our senses?
• Locke would say that our knowledge of things is
  really our knowledge of ideas of things
• He divides the qualities of objects into two types

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Primary Qualities

• These qualities are completely objective
• These are qualities of an object that are
  distinct from our perception
• They can be measured objectively
• These objects would exist whether we perceived
  them or not

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Secondary Qualities

• These qualities are completely subjective
• Such qualities are those which we discern from an
  object through observation
• They are qualities that we impose on an object
  (colour, texture, smell)

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Enter George Berkeley

• Berkeley agrees with Locke in that ideas
  originate with sensory experience
• Berkeley, however, thinks that primary qualities
  could be considered to be subjective
• Berkeley asserts that only minds and ideas exist
• No entity can exist without a perceiver -
  subjectivism

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Solipsisms

• If you interpret Berkeley to the extreme (minds
  and perceivers), you end up with a solipsism
• A solipsism is an extreme form of subjective
  idealism which contends that only I exist and
  that everything else is a product of my
  subjective consciousness

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The dilemma

• Do objects cease to exist when I am not observing
  them?
• Berkeley claims that things continue to exist
  even when no human mind is perceiving them
  because
• Wait for it
• Because God is forever perceiving them!
• Therefore, objects do continue to exist outside
  of our individual perception

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David Hume and Skepticism

• Hume will push Lockes view to the limit
• Skepticism asserts the view that varies between
  doubting all assumptions until proved and
  claiming that no knowledge is possible
• For Hume, perception senses experience

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Perception according to Hume

• For Hume, perceptions take two forms
• Impressions the initial experience of an object
  or event
• Ideas the memory of an object or event
• Hume asserts that prior sense impressions help us
  make sense of our world
• Without impressions, there can be no ideas

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The dilemma

• What about an external reality?
• According to Hume, external reality is an
  illusion because there is no way to verify its
  existence
• So
• With no external reality there is
• No self
• No God

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Immanuel Kant to the Rescue

• Kant wants to deal with the skepticism of David
  Hume
• He rejects the rationalist claim that all
  knowledge is a priori
• Kant also rejects the empiricist claim that all
  knowledge comes only from sense perception

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Kantian Epistemology

• For Kant, knowledge comes from two sources
• Content which is derived from our sensory
  experience
• Form which is derived from our reason
• In epistemology, this is known as Transcendental
  Idealism

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Transcendental Idealism

• All knowledge is acquired by our innate search
  for causal explanations for events
• Because we are constantly looking for the causes
  of events, our mind is an instrument that imposes
  structure on the world in which we live
• The world around us is a world that our mind
  constructs and the world must conform to our minds

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The dilemma

• What about a mind-constructed world that does not
  conform to causal laws? (dreams)
• Kant argues that events must be verified by
  causal effects

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The Scientific Method

• Inductive reasoning that is, the process of
  reasoning to probable explanations or judgements
• Francis Bacon investigated nature through
  observation and experimentation
• John Stuart Mill used methods of induction to
  find generalizations to support observations

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Features of the Scientific Method

• Accumulate observations
• Infer laws and form generalizations
• Confirm findings
• Inductionists would follow the criterion of
  simplicity the belief that the world follows
  simpler rather than complex laws

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The Hypothetical Method

• This methodology moves beyond generalizations
• William Whewell would claim that scientific
  advancements are made by creative guessing
  hypothesis which is a general assumption,
  statement, or theory of explanation, the truth of
  which is under investigation

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Hypothetical Method

• So, scientific inquiry sets about to prove or
  verify the hypothesis
• Karl Popper contended that scientific hypotheses
  must be capable of being falsified through
  empirical observation
• Falsifiability is the process of repeatedly
  attempting to prove an hypothesis false
• If the hypothesis survives, it is correct

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Notes on the Scientific Method

• It incorporates elements of empiricism,
  rationalism, and transcendental idealism
• It relies on inductive reasoning, generalization,
  and repeated confirmation of new observations
• It uses hypotheses, verified through observation,
  to guide research
• It must be falsifiable the theory must make
  predictions that, it wrong, can be shown to be
  false by observation

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• Theories must be widely accepted by the community
  of scientists
• Scientific theories must meet five criteria
• Accuracy
• Consistency
• Reliability
• Interconnectedness
• Inspirational