# GEOG 199: Logic and Rationality

Only opportunity to take this one-time course.

“You are wrong,” “no, I am not,” “yes, you are.” Clearly some discussions lead nowhere, and we are seeing more and more of those discussions in international politics, but what does it mean to be wrong or right? Is that all a matter of perspective, power, and intentions, or is there something real underlying certain statements – usually called truths –, but not others – called by many different names, e.g., lies, errors, fake, or more neutral falsities? All over the world some proclaim, we live in a post-truth age and equate truth with dogma or ideology. This is not happening for the first time. The protagonist in Orwell’s 1984, a novel written in 1948 which is since recently becoming a best-seller again, works for the Ministry of Truth, tasked with revising the past, and comes to fight for truth (and freedom and love). Why is it that certain statements are more compelling than others? What makes an argument rational? Why is the existence of truth, whatever it may be, fundamental for rational (useful) thinking?

This course delves into the theory of logic, a mathematical theory and regimen of thought that was fundamental for Europeans to overcome what is today called the Dark Ages, an age of irrationality and cruelty. You will learn how to understand a statement logically (syntax ), how to derive truth and falsity of a sentence under different assumptions of what may be true (semantics), and how to draw conclusions under such uncertainty (proof theory). We will discuss what a rational argument is and contrast this with invalid argumentation structures employed in associative reasoning.

Finally, we will look into the most recent findings on semantics that are pointing at a new theory of truth, allowing for the first time for a solid grounding of the symbols of logic in perception.

Textbook
W. V. O. Quine. Elementary logic. Harvard University Press, 1980.

Expected Outcomes
Students taking the course will be able to

• understand and distinguish syntax, semantics, and pragmatics of a logical statement as well as the notion of logical inference,
• distinguish classical valid and invalid inference schemata, key to engaging in rational, collaborative discussions suitable to build a common ground between discussants from different (interdisciplinary, international) backgrounds,
• understand the basic principles of recommender systems and other modern artificial intelligence systems built upon machine learning technology so as to employ and leverage these systems competently and responsibly,
• understand both the issue underlying the current world-wide social media crisis and its solution.