1.1 Reasoning and Argumentation

Reasoning has been defined as the “capacity to abstract, comprehend, relate, reflect, notice similarities and differences, etc.” However, logicians usually mean our ability to infer, to grasp that the truth of some statements implies the truth of other statements. An argument is a set of these statements that imply a truth connection between themselves, usually in an attempt to pursuade. Logic is the studying of that reasoning.

Only stating a conclusion is not arguing, that’d be closer to either giving a fact or stating an opinion. If you first state your premises with your conclusion, it then becomes an argument. Such as the following— The ocean is the most beautiful thing. The ocean is blue. Therefore, blue is the most beautiful color. This is an argument, though you may disagree that the ocean is the most beautiful thing, the ocean’s blue-ness, or even if beauty is derived from color.

1.2 Why Study Logic

Arguments being an attempt to pursuade, are found everywhere in life. Studying logic will allow you to spot good vs. bad arguments, so that you’re pursuaded by good arguments, and disuaded from bad arguments. It’ll also allow you to craft arguments, and beyond public speaking or sales, this has its application in computer programming, and even your own internal reasoning for systematic thinking.

1.3 Introductory Terms

Argument

A group of statements, one of which is meant to be supported by the other(s).

Premise

A statement that is meant to support the conclusion of its argument.

Conclusion

A statement that is meant to be supported by the premise(s) of its argument.

Standard Form

A written argument in which the premises are listed first and seperated from the coclusion by a horizontal line.

Statement

A sentence that makes an assertion

Truth Value

The result of an assertion being either true or false

Supports

A quality of a statement in relationship to another statement to persuade of the second statements truth value.

Premise Indicators

As, Because, For, For the reason that, Given than, In that, On account of, Since

Conclusion Indicators

Accordingly, Consequently, Hence, It follows that, Must, So, Therefore, Thus

1.4 Deductive Arguments and Inductive Arguments

Deductive Arguments are arguments in which the premises support the conclusion in such a way it would be impossible for the conclusion to be false. Meanwhile an Inductive Argument the premises support the conclusion to only be likely.

Inferential claim indicator words are the words found in the conclusion that hint towards whether an argument is deductive or inductive. Additionally, we must treat the argument as it identifies itself.

1.5 Recognizing Arguments

It’s important to learn to distinguish arguments from non-inferential passages. Those statements may have truth values, but lack the supporting two part structure. There’s types of NIP’s: Advice, Conditional, Expository, Illustration, Report, Statement of Belief, Warning, and Explaination. Just because something is on that list, doesn’t mean it can’t be part of an argument, only that it is not an argument in it of itself. Explainations are tricky, as they contain an explanandum— that which must be explained, and explanans— that which does the explaining. Explainations can actually sometimes serve as arguments, only when the explanandum is contentious.

Evaluative Terms

Validity

A property of deductive arguments in which: it is impossible for the premises to be true and the conclusion false.

Soundness

A property of valid deductive arguments in which: all the premises are true.

Strength

A property of inductive arguments in which: it is likely when the premises are true that the conclusion is also true.

The counterpart is Validity, the premises being true or false does not weaken the argument.

Cogency

A property of strong inductive arguments in which: all the premises are true, and no pertinent information is omitted.