Critical Thinking

• We are not born with the ability to think critically; it develops over many years, and requires effort.
• The development of this ability was studied by William G. Perry, Jr.
• He articulated multiple stages for the development of critical thinking. Here is a subset of them:
  • Dualism: Truth is absolute; there is a clear Right or Wrong, and it can be defined by reference to one authority.
  • Multiplicity: There are many different answers, and perhaps more than one authority is right.
  • Commitment: By weighing evidence oneself, rather than relying on authority, it is possible to tentatively come to a current best answer.
• The goal of developing critical thinking is to be capable of open-minded skepticism:
  • Open-minded: Evidence needs to be carefully examined and evaluated; new ideas cannot be dismissed out of hand.
  • Skepticism: What is the evidence against the assertion? What else needs to be shown to support the idea? Is there an alternative explanation?
• It is often frustrating when your favorite hypothesis is refuted by experimental evidence; but this often leads to a deeper understanding of how nature works.
• Learning to think critically will help you in any field of endeavor, not just in this course.