PHIL 1100 -- Ethics
Prof. Chris Heathwood

University of Colorado Boulder

Presenting, Explaining, and Evaluating Arguments

On an exam you may be asked to Present, Explain, and Evaluate some argument.  Here is what you are being asked to do.


To present an argument, just write it down in the standard line-by-line format.  You will be asked to Present, Explain, and Evaluate an argument on an exam only if it is one you have already seen in class.  On an exam, the argument you give needn't have exactly the same words as the argument we gave in class, but all the premises and the conclusion should mean the same thing.


Explaining an argument is the most significant and difficult part of Presenting, Explaining, and Evaluating Arguments.  To explain an argument, you need to do two things for each premise of the argument:

(1) define any terms in the premise that need defining;
(2) give the rationale for the premise.

To do step (1), give the definition or otherwise explain the meaning of any technical or semi-technical term that appears in the premise.  Technical or semi-technical terms are special words or phrases that we have defined in class or to which we have otherwise called attention (they often appear in red on slides).  Sometimes defining a technical term requires using another technical term.  If this happens, you need to define the additional technical term as well.  If you're not sure whether to define a term, you may as well define it.  (On an exam, you don't need to define a technical or semi-technical more than once on that exam.)  

To do step (2), give the reason the premise is supposed to be true.  You are, in effect, giving an informal little argument for that premise.  Even if you happen to think that the premise is false, you still need to be able to give the reason that a proponent of the argument would give for thinking that the premise is true.  

You don't need to do anything for the conclusion when you explain an argument. (The premises, which you have already presented and explained, entail the conclusion, so the conclusion has already been "taken care of").


To evaluate an argument is to say what you think of it.  In particular, say whether you think it is sound.  If you do not think that the argument is sound, you need to identify the premise that you think is false, and then say why you think it is false.  Sometimes, there is a "right answer" to the Evaluate step.  Some of the arguments we discuss are clearly unsound.  If you say on an exam that such an argument is sound, that's a wrong answer.  But in other cases, there is "no right answer" – that is, it's controversial what the right answer is.  In such cases, you can have whatever opinion you want of the argument and get full credit -- so long as you clearly explain and adequately defend your view.



Possible exam question:

Present, Explain, and Evaluate the "Lack of Time" Argument against utilitarianism.

What follows is an answer that would receive a perfect score.


The "Lack of Time" Argument
P1. If AU is true, then it is always right to calculate utilities before acting.
P2. Sometimes it is not right to calculate utilities before acting.
C. Therefore, AU is not true.


Premise 1 – Definitions:

AU is the theory that says that an action is morally right if and only if it maximizes hedonic utility.

The hedonic utility of an action is the amount of pleasure the act would produce minus the amount of pain it would produce, for anyone, anywhere, at any time.

An act maximizes hedonic utility when no alternative to it has a greater hedonic utility.

An action is an alternative of another act when it is something else the agent could do instead of that act.

To calculate utilities is to figure out what all of your alternatives are, what the hedonic utility of each one is, and which one has the most hedonic utility.

Premise 1 – Rationale:

According to AU, we are required to maximize hedonic utility.  But the only way to do that is to know which of your alternatives maximizes hedonic utility.  And the only way to know that is to calculate utilities.  Thus, AU requires us always to calculate utilities.

Premise 2 – Definitions

(no new definitions)

Premise 2 – Rationale:

This premise can be supported by considering a specific case in which it is obviously not right to take the time to calculate utilities.  Suppose, for example, that your kid runs out onto Broadway.  Suddenly, the SKIP bus appears and is going to run him over in five seconds – unless you grab him and pull him off the street.  It would obviously be the wrong thing to do in this situation to spend the time to figure out what all of your options are, and how much pleasure and pain would result from each.  If you do that, your kid will be run over by the bus.  Thus, it is clearly not always right to calculate utilities before acting.


Although this argument might seem right at first glance, it is actually unsound.  P1 is false.  And, ironically, the very case we used to show that P2 is true shows that P1 is false.  In that case, not only is calculating utilities obviously wrong, it also doesn't maximize hedonic utility!  This is because calculating utilities would lead to your kid being hit by the bus, which would cause lots of suffering in lots of people and deprive him of lots of future pleasure.  Thus, even AU agrees that it is not always right to calculate utilities before acting.