Phil 101: Logic

1. Phil 101: Logic Spring 2013

2. Introduction: Today’s Class • Mechanics of course and expectations • Syllabus • Class website and message board • Introductory readings • Chapter 0: Introduction and comments about survey • Homework: Read A Prelude to Logic Ch 1 and Logical Possibility

3. The Agenda • Critical Reasoning (“Informal Logic”) • The real informal fallacies • A survey of some philosophical problems (this is a philosophy course! • Introduction to concepts that figure in the study of formal logic • Symbolic Logic • Propositional Logic: translation, truth tables, truth trees and proofs • Introduction to predicate logic (if time permits): translation, equivalences, identity and definite descriptions

4. Behavioral Economics & the Real Fallacies • Bounded Rationality: humans are not (1) fully informed, (2) strictly rational, (3) completely self-interested. • People have two different thinking systems. • People are subject to cognitive biases—systematic errors of perception and judgment. • People are good at perceiving causation but very bad at statistical reasoning…as the results of our survey show.

5. Spring 2013 Logic Students Survey

6. Spring 2013 Logic Students Survey

7. Spring 2013 Logic Students Survey

8. A List of Cognitive Biases (Abridged!) • Loss aversion – "the disutility of giving up an object is greater than the utility associated with acquiring it” • Planning fallacy – the tendency to underestimate task-completion times, often caused by taking the “inside view” rather than comparing to a reference class in making predictions. • Zero-risk bias – preference for reducing a small risk to zero over a greater reduction in a larger risk. • Halo effect – the tendency for a person's positive or negative traits to "spill over" from one area of their personality to another in others' perceptions of them (see also physical attractiveness stereotype). • Representativeness heuristic – the tendency to estimate the likelihood of an event by comparing it to an existing prototype we think of as typical.

9. The List continues… • Anchoring– the tendency to rely too heavily, or "anchor," on a past reference or on one trait or piece of information when making decisions. • Confirmation bias – the tendency to search for or interpret information or memories in a way that confirms one's preconceptions.[ • Framing effect – drawing different conclusions from the same information, depending on how or by whom that information is presented. (includes default reasoning) • Just-world hypothesis – the tendency for people to want to believe that the world is fundamentally just, causing them to rationalize an otherwise inexplicable injustice as deserved by the victim(s). • Availability heuristic – the tendency to overestimate the likelihood of events with greater "availability" in memory, which can be influenced by how recent the memories are, or how unusual or emotionally charged they may be. Nudge

10. Anchoring

11. Confirmation Bias

12. Availability Error

13. Real World Consequences!

14. Paternalism? Liberty Limiting Principles • The Harm Principle • Legal Moralism • Legal Paternalism

18. Libertarian Paternalism

19. Welcome to Philosophy!

20. Possibility At our next class meeting we’ll talk about possibility…