To argue for a moral postion by showing how it is similar to another type of case for which our intuitions are clear. Such arguments are based on the presupposition that similar cases ought to be decided similaryly.
Begging the Question
To assume the very thing that your were suposed to prove.
To attribute a property to an object that does not and cannot apply to it.
When one has two options and they are both bad or problematic.
To use the same word in two different senses in an argument without identifying the change in sense.
The reasons given in an argument to support the conclusion.
Reductio ad absurdum
To show that your opponents reasoning leads to an absurd conclusion.
To argue that allowing one type of action will eventually lead to similar actions that are morally worse.
An arguemt tha is valid AND has true premises.
An argument is valid if the truth of its premieses would guarantee the truth of its conclusion.