[1.] Introduction: Arguments Some of the material in this
section of notes, as well as in the next few sections, should be
familiar to you from Critical Thinking (PHIL 2020), which is a
prerequisite for this class. The word “logic” has more than one
meaning: 1. the discipline of logic = the area of inquiry that
studies reasoning and arguments; it is particularly concerned
with what distinguishes good arguments from bad ones. (In this
sense of the word “logic,” it refers to one of the four
traditional branches of philosophy, along with metaphysics,
epistemology and ethics.) 2. a symbolic logic = an artificial
language (i.e., a language deliberately created by human beings,
as opposed to “natural languages” like English, French,
Japanese, Urdu, etc.) the purpose of which is to help us to
reason in a clearer and more precise way. (The creation and
study of symbolic logics is a part of the discipline of logic.)
This course deals with logic in both senses of the word. We will
use a symbolic logic—an artificial lan