This is my attempt to explain your paper assignment and grading standards in ordinary English. The official grading rubric is posted as well, and that's what I actually use to grade the paper.

The paper's audience

The audience for your paper is a reasonable person who has taken this class, learned and understood everything we have covered, and starts off disagreeing with your thesis.

Parts 1 and 2

The general idea behind parts 1 and 2 is that, together, they should be able to convince your audience that your thesis is true. In Part 1, you argue for your thesis. In Part 2, you respond to the objections that your classmate will definitely know about because they came up in class or in the reading.

I will grade part 1 without reading any of parts 2, 3, and 4. Similarly, I will grade part 2 without reading 3 or 4. So what you say in these parts has to stand on its own.

Part 1
Part 1 must explain what your thesis means. Any unclear or ambiguous terms should be explained. Given this explanation, your audience members should be able to think of example situations and determine if these fit the antecedent(s) of the conditional(s) in your thesis. (If this is not possible, then no one can be convinced by Part 1, since no one knows what you are trying to claim)

Part 1 must contain an argument for your thesis. This is going to consist of articulating the reasons for and against the things your thesis says are wrong and permissible, showing which reasons are more weighty and which are less weighty, and saying how all this supports your thesis. In saying what the relevant reasons are, and how weighty they are, you must give evidence that could convince the audience. The argument should address every aspect of your thesis: if your thesis discusses a number of factors that make an action wrong, you must argue for each of them.

Part 2
Part 2 will bring up all the various issues your classmates are likely to have with your thesis or part 1. How do you know what these are? These are the things that came up in class or in the readings that are potentially relevant to what you said in part 1.

In part 2, you will go through each topic we've covered in class, and explain if there is anything that came up in addressing that topic, or in the reading on the topic, that seemingly poses problems for your view. Sometimes there will not be, and you can say that. Of course, the topic you are writing won't have been explicitly addressed in each reading; but it's your job to see if there is still a connection between each topic/reading covered in class and what you are talking about. When the reading/class discussion raised an objection to your view, you must explain what the objection is.

When there is an objection to your view, you must also say why the objection is mistaken. That is, you must try to convince someone who raises that objection that your view is still correct.

The majority of your grade for part 2 is based on whether you correctly identify the objections to your view and respond to them in a way that could convince someone who disagreed with you.

Part 3
In Part 3, you must give a reasonable, and novel, counterexample to your thesis.

This must be a specific counterexample - a specific situation that seems to show that your thesis is false. It must be significantly different from any we have covered in class, or anything that was in the reading. You must clearly explain the specific situation that is your counterexample. And you must clearly explain why someone would think that this is a strong counterexample to your thesis.

To get an A, you must both give a counterexample to your thesis that could convince a reasonable person that your thesis is false, and you must also clearly explain why a reasonable person could be convinced by it, in a way that shows that you understand (some of) those who disagree with you.

Part 4
In Part 4, you must respond to the counterexample given in Part 3. You may not change your thesis, nor change any part of the objection from Part 3.

Your response should be able to convince a person who was originally compelled by the example in Part 3.

If your response shows that there is a better counterexample to your thesis than the one in Part 3 (e.g. it focuses on a detail of Part 3 that could easily be changed to make Part 3 a better counterexample), that is bad for your grade.

If Part 3 is a weak or bad counterexample to your thesis, then you cannot get a good grade for Part 4; this is because Part 4 does not demonstrate your ability to really engage with people who disagree with you.