Argument Reconstruction

Formal Validity and Anthememes

  • Formal Validity: A property of arguments where true premises guarantee the truth of the conclusion.

    • Formal validity is not concerned with the actual truth of the premises, only that if the premises are true, the conclusion must be true.

  • Anthememe: An argument with a suppressed premise, often seen in one-premise arguments.

    • Task of the evaluator is to discern the unstated assumptions behind the argument.

    • Example:

    • Argument: "Abortion is murder; therefore, abortion is wrong."

    • Suppressed premise: "Murder is wrong."

      • Resulting formal validity: Murder is wrong; abortion is murder; therefore, abortion is wrong.

    • Conclusion: Valid argument. However, the truth of the conclusion is still to be determined (this relates to soundness).

Soundness vs. Validity

  • Soundness: An argument is sound if it is valid and all its premises are true.

  • Differences between Validity and Soundness:

    • Validity focuses on formal structure; soundness requires both valid structure and true premises.

    • An argument can be valid with false premises (e.g., "If pigs can fly, then all flowers are green.") but not sound.

Examples of Arguments and Their Validity

  • Example of a non-moral claim:

    • An argument can be crafted to show validity even if the conclusion seems implausible (e.g., "Pink pigs fly 98% of the time").

  • Self-defense and its relation to murder:

    • Question: Is killing in self-defense considered murder?

    • Legal outcome: Killing in self-defense can lead to a verdict of not guilty.

Begging the Question

  • Begging the Question: A formal fallacy where an argument assumes its conclusion in its premises.

    • Example: "Murder is wrongful killing; abortion is murder; therefore, abortion is wrong."

    • This presumes abortion is wrong without independent justification.

  • To avoid begging the question, a clearer formulation is needed: e.g.,

    • "Abortion is the intentional killing of another person; the intentional killing of another person is wrong; therefore, abortion is wrong."

Contestable Premises and Arguments

  • Premises in discussions of complex moral issues such as abortion are often highly contested.

  • The necessity of establishing definitions and clarity around key concepts such as "person" arises frequently in these debates.

Non Sequitur Arguments

  • Non Sequitur: Refers to conclusions that do not logically follow from the premises.

  • Essential to evaluate connections; suppressed premises must relate logically to the conclusion.

    • Example: "A woman has the right to do what she wants with her body; abortion is an act that has to do with her body; therefore, a woman has the right to an abortion."

    • Possible suppressed premise needed: "A woman has the right to control her own body."

The Role of Moral Premises

  • Inquiry must be made into whether the arguments accurately reflect moral positions.

  • Moral arguments must address contested premises involving rights to one's body and the implications of self-defense and autonomy.

Intuitive Logic and Premises

  • Intuitive Logic: Focus on the movement and flow of arguments rather than strict formal logic.

  • Good arguments demonstrate a driving force toward the conclusion.

    • Bad arguments may lack connection or movement between premises, making them appear disjointed.

Definitions of Key Terms in Arguments

  • Argument: A series of claims with premises supporting a conclusion.

  • Validity: Guarantees truth of conclusion based on premises.

  • Soundness: A valid argument with true premises.

Evaluating Arguments

  • Avoid claiming arguments can be 'true' or 'false'; arguments are either valid or invalid, sound or unsound.

  • Arguments should connect premises logically and leads to a defensible conclusion based on moral or empirical claims.

Practical Application of Arguments in Debates

  • Discuss complex societal issues (e.g., pornography, climate change) by evaluating claims made for ethical arguments.

    • Example: "Each person has a duty to limit their carbon footprint; we should limit activities that excessively consume carbon; therefore, we should limit childbearing because it is carbon expensive."

  • Real-world implications involve addressing whether carbon consumption is necessary for a flourishing life and establishing a moral framework supporting the conclusion.

Methodology for Constructing and Evaluating Arguments

  1. Identify the conclusion of the argument first.

  2. Ask what justifications the author has for their conclusion.

  3. Ensure that the premises work together in a manner supporting the conclusion.

  4. Evaluate moral claims, acknowledging where differing views may challenge the conclusions drawn.

  5. Practice constructing arguments with clarity while addressing suppressed premises, faulty assumptions, and potential fallacies.

Grades and Evaluations

  • For assignments, the grading rubric includes assessing the strength of the argument (10 points), the validity of premises (5 points), and clarity of writing (5 points).

  • Emphasis on constructing logically sound and morally robust arguments, focusing on content and coherency without resorting to superficial proofs or unsupported claims.