PhilosophyLesson 3 of 4 in the course Logic and Reasoning

Deduction, Induction, and Abduction: Validity and Evidence

5 flashcards · 5 quiz questions · 5 match pairs · 5 fill-in sentences · English

Save course
Lesson progress
0 / 5

Your progress is kept in this browser only.Sign up to save it

Summary

This lesson introduces the three broad types of inference and focuses on how deductive reasoning works. Deduction matters because a valid deductive argument can guarantee that its conclusion is true if its premises are true.

An inference is reasoning that moves from information or premises toward a conclusion. Inferences are commonly classified as deductive, inductive, or abductive.

All flashcards

What is validity?
An argument is valid when it is impossible for all its premises to be true and its conclusion false; validity does not establish that the premises are actually true.
What is inductive reasoning?
Reasoning that uses observations, experience, or accepted general beliefs to support conclusions that are probable but not guaranteed.
What is abductive reasoning?
Reasoning from evidence toward a hypothesis that would explain it, often by selecting the best available explanation.
What is a counterexample to a deductive argument?
A possible case in which all the premises are true and the conclusion is false; such a case shows the argument is invalid.
What is an explanatory virtue?
A feature that tends to make a hypothesis a stronger explanation, such as scope, simplicity, conservativeness, or depth.

Quiz questions

  1. Which argument form has the pattern If X, then Y; not X; therefore not Y?Answer: Denying the antecedent.
  2. What makes a possible case a counterexample to a deductive argument?Answer: All premises are true, while the conclusion is false.
  3. What does the principle 'extraordinary claims require extraordinary evidence' recommend?Answer: Claims that conflict with extensive accepted knowledge need especially strong evidence.
  4. A clinician proposes a diagnosis to explain a patient's symptoms and test results. Which reasoning role is being used?Answer: Abductive reasoning.
  5. What does an invalid deductive argument establish about its conclusion?Answer: The premises do not guarantee it, though it may still be true.

Based on Introduction to Philosophy by Nathan Smith (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.

More in Philosophy

All Philosophy lessons
PhilosophyLogical Conditionals and Universal Affirmative Statements5 flashcards · 5 quiz questions · 4 gamesPlay free →PhilosophyJTB, Gettier Cases, and Proposed Conditions for Knowledge5 flashcards · 5 quiz questions · 4 gamesPlay free →PhilosophyPresentist, Contextualist, and Hermeneutic Readings of Philosophy5 flashcards · 5 quiz questions · 4 gamesPlay free →PhilosophyIdentifying and Evaluating Arguments: Premises, Inferences, and Evidence5 flashcards · 5 quiz questions · 4 gamesPlay free →PhilosophyPhilosophical Accounts of Self, Persistence, and Personal Identity5 flashcards · 5 quiz questions · 4 gamesPlay free →PhilosophyClassical Indian Philosophy: Vedic Thought, Samkhya, Yoga, and Darshanas5 flashcards · 5 quiz questions · 4 gamesPlay free →