"Rather than defend myself" <--Why are we allowed to use an infinitive after this preposition?
Rather than defend myself, I took a deep breath and tried to see his point of view.
In the above sentence, than is a preposition. So I thought the verb defend should have a form of -ing like than defending myself.
Why is the verb defend in the plain form?
I think "than" is being used as a subordinating conjunction - introducing an exception or contrast. So I am not sure your concern applies.