Propositions

§1.1.

Before we discuss arguments in earnest, it will be helpful to say a bit about propositions, which are the smaller units of thought from which arguments are composed. A proposition is the sort of thought that is capable of being true or false, believed or disbelieved, and asserted or denied. Such thoughts are asserted by declarative sentences. Here are some examples:

1. Healthy grass is green.	6. Stalin was evil.
2. O. J. Simpson killed Nicole Brown.	7. Donald Trump is the 45th President of the United States.
3. Twice two is four.	8. Either Trump or a Democrat will win the 2020 election.
4. Twice two is five.	9. Donald Trump should be impeached.
5. Many diseases are caused by bacteria.	10. Hillary Clinton would have been an awful president.

The proposition is not the same thing as the sentence asserting it because the same thought can be asserted by different sentences. For example, here are several different ways of asserting Proposition 3 from the list above:

3a. Twice two is four.

3b. Two times two is four.

3c. 2 x 2 = 4

3d. Deux fois deux c'est quatre.

3e. 兩次兩次是四次。