>>11919357E&M is the basic course in field theory. i had the same question when i was a grad student: “well, when do i learn field theory?” the answer was “oh, didn’t you pass that Jackson course? that’s the field theory course.”
at the time i didn’t appreciate it, but classical field theory basically amounts to EM and GR. so if you want to learn classical field theory, then Griffiths EM is the place to start
