The rule of thumb or the golden rule?

[Leontiskos]

Interesting thread. @Tom_Storm and I were actually just talking about the Golden Rule, beginning around this post.

@MoK

The rule of thumb, however, states that each person has all the right to his/her life (self-ownership) and has no right to the lives of others (non-ownership).

First, I would like to note that the negative golden rule can be derived from the rule of thumb. Here is the argument in syllogism form:

P1) You have no right to another person’s life (non-ownership)
C1) If so, you have no right to violate their lives (from P1)
P2) If you don’t want others to violate your life (self-ownership)
C2) Therefore, you must not violate others in the way you reject being violated (from C1 and P2)

Can you explain P2? It looks like an ‘if’ without a ‘then’.