Personal justification
When, if ever, is it legitimate to try to convince someone else to believe something on the basis of a premise that you yourself reject?[1] I'm not sure I exactly can pinpoint the meaning of legitimate here. We can think of it as being able to be defended with logic or justification,[3] or reasonable and acceptable.
Suppose the following scenario, that you often throw loud parties late into the night close to my bedroom. I want to convince you to stop or at least quiet down. Fortunately, you think that every citizen ought to obey the law. I disagree, for I am an anarchist bent on undermining all governments and laws. Still, I want to get a good night’s sleep before the protest tomorrow, so I might argue that it is illegal to make that much noise so late, and you ought to obey the law, so you ought to stop throwing such loud parties. This argument can show you that you are committed to its conclusion, even if I believe that its premises are false.[1]
We can say that I gave you a good reason to believe that you ought to stop, so I personally justified my reasons. I could have also explained my reasons, if I simply said that I want to have a good night's sleep before the protest. Here we show not what reasons there were to perform it but what were the agent's reasons for performing it[2], therefore we explain but not justify, in that we do not provide a good normative sense in doing so, even though we do not provide it in justifying, with it being personal rather than normative.
In this scenario, we could argue that the use of the subject's beliefs that contradict the agent's could deem the argument illegitimate although perfectly justifiable. What could make it legitimate is that if we consider the anarchists point of view, that in an anarchists society there would be no need for a law to enforce this behavior of a subject, in that the subject will behave so in his own free will. In this view, we can indeed conclude the legitimacy of the agent's argument.
Or, if we take the "being able to be justified" approach, we can just stop at the point where we say that the agent just wants a good night's sleep before the protest, and that is why he uses the premise or belief that he doesn't accept himself. So the difference is somewhere in the moral standpoint of the agent.
[1] Understanding Arguments. Walter Sinnott-Armstrong and Robert J. Fogelin. 2009.
[2] Stanford Encyclopedia of Philosophy. Reasons for Action: Justification vs. Explanation. 2009.
[3] Oxford Dictionary of US English.
Suppose the following scenario, that you often throw loud parties late into the night close to my bedroom. I want to convince you to stop or at least quiet down. Fortunately, you think that every citizen ought to obey the law. I disagree, for I am an anarchist bent on undermining all governments and laws. Still, I want to get a good night’s sleep before the protest tomorrow, so I might argue that it is illegal to make that much noise so late, and you ought to obey the law, so you ought to stop throwing such loud parties. This argument can show you that you are committed to its conclusion, even if I believe that its premises are false.[1]
We can say that I gave you a good reason to believe that you ought to stop, so I personally justified my reasons. I could have also explained my reasons, if I simply said that I want to have a good night's sleep before the protest. Here we show not what reasons there were to perform it but what were the agent's reasons for performing it[2], therefore we explain but not justify, in that we do not provide a good normative sense in doing so, even though we do not provide it in justifying, with it being personal rather than normative.
In this scenario, we could argue that the use of the subject's beliefs that contradict the agent's could deem the argument illegitimate although perfectly justifiable. What could make it legitimate is that if we consider the anarchists point of view, that in an anarchists society there would be no need for a law to enforce this behavior of a subject, in that the subject will behave so in his own free will. In this view, we can indeed conclude the legitimacy of the agent's argument.
Or, if we take the "being able to be justified" approach, we can just stop at the point where we say that the agent just wants a good night's sleep before the protest, and that is why he uses the premise or belief that he doesn't accept himself. So the difference is somewhere in the moral standpoint of the agent.
[1] Understanding Arguments. Walter Sinnott-Armstrong and Robert J. Fogelin. 2009.
[2] Stanford Encyclopedia of Philosophy. Reasons for Action: Justification vs. Explanation. 2009.
[3] Oxford Dictionary of US English.