P H I L O S O P H Y

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P H I L O S O P H Y

• A Text with Readings
• TENTH EDITION
• M A N U E L V E L A S Q U E Z

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P H I L O S O P H Y

• There are two common views regarding the sources
  of knowledge rationalism and empiricism.

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P H I L O S O P H Y

• Rationalism states that some knowledge is based
  on reason rather than on sensory perception.

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P H I L O S O P H Y

• René Descartes was a rationalist concerned with
  discovering something that he could hold as true
  beyond any doubt. He concluded that no one could
  doubt that a human is a thinking being, that a
  thinking thing exists, that God exists, and that
  the world exists. All of this, he claimed, could
  be established by reason alone.

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P H I L O S O P H Y

• Empiricism states that all knowledge comes from
  or is based on sensory perception and is a
  posteriori.

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P H I L O S O P H Y

• John Locke held that objects have primary
  qualities that are distinct from our perception
  of them, such as size, shape, and weight. He also
  believed that they have secondary qualities that
  we impose on them, such as color, smell, and
  texture. We know the objective world through
  sensory experience, which is a copy of reality
  and which gives us our ideas of reality.

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P H I L O S O P H Y

• According to George Berkeley's subjectivism, we
  know only our own ideas. Carried to an extreme,
  this position can become solipsism, the position
  that only I exist and everything else is a
  creation of my subjective consciousness.

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P H I L O S O P H Y

• David Hume pushed Locke and Berkeley's empiricism
  to its logical conclusion. Arguing that all
  knowledge originates in sensory impressions, Hume
  distinguished between two forms of perceptions,
  impressions and ideas.
• Impressions are lively perceptions, as when we
  hear, see, feel, love, or hate.

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P H I L O S O P H Y

• Ideas are less lively perceptions they are
  reflections on sensations.
• Hume denied that there is any logical basis for
  concluding that things have a continued and
  independent existence outside us. He denied the
  possibility of any certain knowledge, arguing
  that both rationalism and empiricism are
  inadequate to lead to truth and knowledge. He is
  thus termed a skeptic.

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P H I L O S O P H Y

• Immanuel Kant's transcendental idealism, an
  alternative to empiricism and rationalism,
  distinguishes between our experience of things
  (phenomena) and the things as they are (noumena).
  The mind, claimed Kant, possesses the ability to
  sort sensory experiences and posit relationships
  among them. Through an awareness of these
  relationships, we come to knowledge.

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P H I L O S O P H Y

• Inductionism is the view that all science is
  based on the process of sensory observation,
  generalization, and repeated confirmation. This
  process is often used to establish scientific
  laws, and simplicity is one criterion for
  choosing among competing generalizations.

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P H I L O S O P H Y

• The hypothetical method view says that science is
  also based on the creative formulation of
  hypotheses whose predictions are then tested and
  used to guide research. Karl Popper argued that
  falsifiability is a criterion of scientific
  theories.

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P H I L O S O P H Y

• Thomas Kuhn argued that scientific theories are
  those that are widely accepted by a community of
  scientists. They are the basis of paradigms that
  guide research but that are abandoned in a
  scientific revolution, when too many anomalies
  appear that cannot be accounted for by the
  paradigm. Scientific theories must be accurate,
  consistent with other widely accepted theories,
  capable of explaining phenomena other than those
  they were developed to explain, capable of
  organizing phenomena that were previously thought
  to be unrelated, and fruitful insofar as they
  generate new research and new discoveries.