Structure of Arguments

     Arguments in logic are composed reasons offered for a conclusion. ("argument" in logic does not carry the everyday connotation of a quarrel ie: shouting match).

     Discover the presence of an argument by understanding the author's intention of proving a statement by offering reasons or evidence. Question 1: is there an argument?

1. The author uses argument indicators (see below) signifying the presence of an argument.

1. (1) Since the solution turned red when the indicator was added, (2) it is acidic, inasmuch as acidic substances react with this indicator to form a red color.

2. The passage under question implicitly provides an answer to the question "What are you trying to prove?"

1. (1) The types of sentences you use are quite varied. (2) I've noticed that your essays are quite sophisticated. (3) You have been learning much more about sentence structure.

1. [The conclusion is statement (3)].

Do not use “This paper shall,” or “In conclusion.” Simply make your statements.

Diagramming Arguments

     In order to analyze simple and complex arguments, we will find it useful to construct a diagram of the structure of the argument that details the relations among the various premises and conclusions.

     A conclusion of one argument can become a premise for another argument,  just as a daughter in one family can become a mother in another family.

1. In analyzing the structure of an argument, whether simple or complex, the all-important first step is to find the conclusion. Here are some specific suggestions as to how to find the conclusion.

1. The conclusion might be evident from the content and context of the paragraph structure. The sequence of sentences is often an indication of the conclusion. Organizing sentences from most general to specific is a common form of structuring a paragraph or passage. Organizing from specific to general is less common. With this in mind the conclusion is most often the first sentence in a paragraph, but sometimes the last.

1. (1) John didn't get much sleep last night. (2) He has dark circles under his eyes. (3) He looks tired.

1. The conclusion is the first sentence.

2. Nevertheless, the conclusion can occur anywhere in the paragraph, especially if the passage has not been revised for clarity. Usually, if a conclusion is not the first or last sentence, a conclusion indicator is present, or the last sentence is presented as an afterthought with a premise indicator.

(1) Studies from rats indicate that neuropeptide Y in the brain causes carbohydrate craving, and (2) galanin causes fat craving. (3) Hence, I conclude that food cravings are tied to brain chemicals (4) because neuropeptide Y and galanin are brain chemicals.

Argument Indicators: Premise Words

Because	After all	For	For the reason
Since	In light of	As	Follows from

     (1)The graphical method for solving a system of equations is an approximation, (2) since reading the point of intersection depends on the accuracy with which the lines are drawn and on the ability to interpret the coordinates of the point.

     (1) Questionable research practices are far more common than previously believed, (2) after all, the Acadia Institute found that 44 percent of students and 50 percent of faculty from universities were aware of cases of plagiarism, falsifying data, or racial discrimination.

Argument Indicators: Conclusion Words

Thus	Indicates that	Consequently	Therefore
So	It follows that	Implies that	Accordingly
Hence	Proves that	For this

     (1) No one has directly observed a chemical bond, (2) so scientists who try to envision such bonds must rely on experimental clues and their own imaginations.

     (1) Coal seams have been discovered in Antarctica. (2) This means that the climate there was once warmer than it is now. (3) Thus, either the geographical location of the continent has shifted or the whole Earth was once warmer than it is now.

Argument Indicators: Equal Status Words

And	Yet	;(semicolon)	In addition
But	However	Nevertheless	Moreover

     (1) Some students absent today are unprepared for this test, since (2) the law of averages dictates that only 10% of students are absent due to illness, and (3) more than 10% are absent.

Complex Arguments

     When working with complex arguments, reconstruct the argument backwards from the conclusion.

     (1) If students were environmentally aware, they would object to the endangering of any species of animal. (2) The well-known Greenwood white squirrel has become endangered (3)as it has disappeared from the Lander Campus (4) because the building of the library destroyed its native habitat. (5) No Lander students objected. (6) Thus, Lander students are not environmentally aware.

     The premise indicators suggest that (2) is a subconclusion of (3) since the indicator "as" connects them, and (3), in turn, is a subconclusion of (4) since the indicator "because" connects those two statements.

• Statement (6) is the final conclusion since it has the conclusion indicator "thus" and the import of the paragraph indicates that this statement is the main point of the argument.

• Intuitively, the structure of the first statement (1)  with statement (5) is a common argument form:
  • If students were environmentally Aware, they would Object to the endangering of any species.
  • No student Objected (to the endangering of the Greenwood white squirrel).

• The negation of the objection clause (5) is logically equivalent to the conclusion (6).
• Hence the whole argument can now be pieced together as: