Reasoning

Logical Reasoning

Definition of Reason: Reason is the ability of a healthy mind to think and make judgments, especially based on practical facts and valid evidence. It involves using logical principles and critical thinking to evaluate claims, draw conclusions, and support arguments.


    Inductive Reasoning:

  • Induction is a type of logical thinking that involves forming generalizations based on specific observations or evidence
  • It is a "bottom-up" approach, moving from particular instances to broader generalizations
  • Although useful, inductive reasoning is inherently probabilistic rather than certain
  • Example:
    • Observation 1: The sun rose in the east yesterday
    • Observation 2: The sun rose in the east today
    • Inductive Conclusion: The sun always rises in the east

    Deductive Reasoning:

  • Deduction is a logical process that starts from general statements or principles and derives specific conclusions
  • It is a "top-down" approach and offers certainty (provided the premises are true and the logic is valid)
  • Example:
    • Premise 1: All humans are mortal
    • Premise 2: Socrates is a human
    • Deductive Conclusion: Socrates is mortal

Syllogisms: A syllogism is a form of deductive reasoning where a conclusion is drawn from two premises. If followed correctly, the conclusion will be logically certain.


    Types of Syllogisms

  • Categorical Syllogism (Classical): Involves statements about categories or groups.
    • All mammals are animals. All dogs are mammals. Therefore, all dogs are animals.

  • Hypothetical Syllogism: Based on conditional "if-then" statements.
    • If it rains, the ground will be wet. It is raining. Therefore, the ground is wet.

  • Disjunctive Syllogism: Uses either/or statements and eliminates one possibility.
    • Either the light is on or off. The light is not on. Therefore, it is off.

  • Polysyllogism: A chain of syllogisms where the conclusion of one becomes a premise in the next.
    • (1) All humans are mortal. Socrates is a human. Therefore, Socrates is mortal.
    • (2) Socrates is mortal. Mortal beings die. Hence, Socrates will die.

    Flawed Syllogisms:

  • Flawed syllogisms have incorrect reasoning even if the premises seem true
  • Example 1:
    • Premise 1: All cats are animals.
    • Premise 2: All dogs are animals.
    • Flawed Conclusion: All dogs are cats.
  • Example 2:
    • Premise 1: The IB Diploma requires hard work.
    • Premise 2: Juan is an IB Diploma student.
    • Flawed Conclusion: Juan works hard. (This assumes all IB students work hard, which may not be true)

Logical Fallacies

Logical fallacies are believable but invalid arguments based on false reasoning. They distort logic and undermine rational discussion.


Common logical fallacies:


    Strawman:

  • Misrepresents an opponent's argument to make it easier to refute
  • Example: "We should regulate guns for public safety" becomes "They want to take all your guns!"

    Post Hoc Ergo Propter Hoc:

  • Assumes that because one event followed another, it was caused by it
  • Example: I wore lucky socks and aced the test. Therefore, the socks caused my success.

    False Dilemma:

  • Presents only two options when more exist
  • Example: "You're either with us or against us."

    Slippery Slope:

  • Argues one step will lead to extreme consequences without evidence
  • Example: Allowing retakes means students will expect to redo entire courses.

    Appeal to Fear:

  • Uses fear to persuade instead of logic
  • Example: "If we don't pass this law, terrorists will destroy us."

    Cherry-Picking:

  • Selects only evidence that supports a view while ignoring the rest
  • Example: Using one scientist to deny climate change despite broad consensus.

    Ad Hominem:

  • Attacks a person's character instead of their argument
  • Types:
    • Abusive: Direct insult ("You're an idiot.")
    • Circumstantial: Points to background or interest ("He's a banker, of course he supports deregulation.")
    • Tu Quoque: Claims hypocrisy ("You lied last week, so you can't talk about honesty.")
    • Guilt by Association: Discredits someone by linking them to another person ("She's friends with a conspiracy theorist.")

Skepticism vs. Denialism

Skepticism is an open-minded and critical approach that values questioning and evidence.
Denialism disguises itself as skepticism but refuses to accept well-supported facts.


    Just Asking Questions:

  • This tactic uses seemingly innocent questions to sow doubt and push an agenda, often pretending not to assert anything
  • Read this article for more information

    Healthy Skepticism Requires:

  • An open mind
  • Respect for evidence
  • Civil and respectful questioning

"Those who will not reason are bigots, those who cannot are fools, and those who dare not are slaves." - George Gordon Byron