“Mapping Moral Reasoning” - Prof. Charles Rathkopf (Iona College)


Do we need new laws to restrict gun ownership in this country? Should doctors be allowed to help very sick patients bring about their own death? Is it wrong to stare at an attractive person as they walk down the street? To deliver a compelling answer to such questions, you have to do more than articulate your opinion. You have to build an argument.

In this course, you will learn how to represent, evaluate, and build moral arguments. Unlike most philosophy courses, ours will take place in a computer lab, and will depend heavily on the use of argument-mapping software that will force you to organize your thoughts precisely.

Like most valuable skills, argument evaluation demands practice. We will therefore spend the majority of each class actively building new argument maps. During each class, students will project their work on the large screen at the front of the room. Together, we will then analyze and improve the work so displayed. As long as you are receptive to feedback from your fellow students, this course will boost your critical thinking skills, and help you to reason clearly about morally complex topics.

Course goals

By the end of the course, students should be able to:

  1. Identify moral arguments in prose
  2. Represent logical properties of moral arguments diagrammatically
  3. Evaluate the strength of moral arguments
  4. Criticize and improve moral arguments

What is an argument map?

An argument map is a great tool for evaluating arguments. It allows you to represent the logical structure of arguments graphically. Graphic representation makes it easy to isolate the logical relationships between individual claims, which is quite difficult to do when arguments are presented in prose form.

You may not have noticed, but the foregoing paragraph presents an argument. Here is that same argument in map format:

Philosophy Course Page

The conclusion of the argument is at the top of the diagram. It is supported by one reason, which is composed of two premises. You’ll notice that the second premise (claim 2.2) is enclosed in square brackets. The brackets signify that claim 2.2 is a hidden premise – it is not explicitly stated in the prose form of the argument, but is implied by it. That premise, in turn, is supported by one reason, which is also composed of two premises. If you compare the sentences in the original paragraph with the sentences in the map, you will notice some subtle but quite important differences. By the end of the first week of class, you will be able to explain why these differences are required, and be able to map arguments of about this difficulty on your own. By the end of the second week, you will be able to map arguments considerably more complex than this.


Assignments will be given during class, and, to a lesser degree, for homework. Most in-class assignments will be done with a partner. It will be impossible to give each student feedback on each map. Instead, we will select a few maps each class, and everyone will participate in figuring out how to improve them. Your homework will be completed on your own. There will not be very much homework, but the homework you do get will be important. It will introduce you to central concepts before we employ them in class, and give you an opportunity to try out mapping on your own.

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