In Section Two of the reading from Kant, beginning on page 26, there are some key things to look for, that I will list below. As usual with Kant, the reading probably gets easier toward the end. So, I suggest that in order to prepare for the Tuesday lecture you follow the outline given below, rather than starting with the beginning of the Section. Then, for Thursday, you can go back and read other parts that you skipped, or reread the parts that you didn't understand the first time.
Imperatives
Kant refers to commands as "imperatives". Examples: "You ought to study." "You will study", if said as a command rather than a prediction. "Everyone ought to be kind". Not all imperatives have to do with morality. E.g., a parent may say to a kid "Hurry up!" That's an imperative, but probably not a moral one.
Kant divides imperatives into two types: hypothetical and categorical. You can read about this distinction by starting in the middle of the second column of page 27. See if you can construct two or three examples of hypothetical imperatives from real life. Here's one to get you started: "Hurry up, if you don't want to be late".
If you understand what a hypothetical imperative is like, you will see why Kant at the top of page 28 says, essentially, that moral imperatives are categorical, not hypothetical. The idea that real moral imperatives are categorical comes from a priori consideration of the nature of morality. A moral obligation would not have the form "If you want to be X, you ought to do Y"--for example, "If you want to be nice, you ought to treat others with respect" is too wishy-washy. A genuine moral law would say, instead, "You ought to treat others with respect". Period. No "if's" "and's" or "but's".
The one basic moral imperative
In the second column of page 28, Kant argues that there really is only one basic moral imperative--one basic moral law, from which all the more specific moral laws can be derived. Recall that Kant has previously argued that we can know a priori
| A genuine moral principle or moral law applies equally to everyone, and |
| a genuine moral principle must be rational, because morality is about our ability to reason about what we ought to do, |
| which implies that a genuine moral principle cannot be self-defeating if applied to everyone. (Recall the example of the irrational law that said it's ok to lie and make a promise you have not intention of keeping, if doing so gets you out of a jam.) |
| A genuine moral principle is categorical, not hypothetical. |
By putting all this together, we seem to get the result that any genuine moral principle must be a categorical imperative that is rational, which means it is a categorical imperative that applies equally to everyone, which means that it is a categorical imperative that would not be self-defeating if everyone were to follow it. This is basically Kant's claim on page 28. Look at the short paragraph about two-thirds of the way down in the second column of page 28.
That short paragraph states Kant's famous "categorical imperative" of morality. He restates it in a slightly different form in the next paragraph.
Examples of how to derive specific moral principles from the basic categorical imperative
Kant finishes this Section with four examples in which he tries to show us how to take the theory presented above and apply it to get some specific moral laws about suicide, borrowing money without intending to pay it back, being lazy about developing one's talents, and helping others who are in need. He divides these into moral duties to ourselves and moral duties to others, but for now the obvious thing to do is to concentrate on his arguments, just to see how purely rational considerations are supposed to lead us to various conclusions about what is the morally right thing or the morally wrong thing to do in regard to these topics.
Respect for others
Kant ends the Section with a general discussion of what he thinks all this means for what is the right way to treat other people. Here he gives us some generalizations of how the moral law can be summarized, with respect to our duties to others. Check this out.