I know I asked the question, but recently I came across a few things. So to counter point..
Game Mechanics -
Whenever you select any module, get get everything in yellow.
If you pick up for example, Shadow work, you get the +1 body, and one of the Roles, as both are in yellow.
For the Higher learning, there Attributes (Skills sometimes) Science Disipline and Arts Discipline that are all in yellow, signifying that you get all of those. But, like any of the options before, there are selections to be made under both disciplines.
Real world
When you go to collage, often you don't just go in for just your major. There is often electorial classes, sometimes having absolutly nothing to do with the main reason why you're going to school. As someone who was going in for video game design, I had to pick up a few science creds and social studies, even english and writing.
Basically, What I'm seeing here is that Science is your Major. So yes, you are correct in that you only get one major, but that is because Art would be your Minor. A secondary field of study that you could be going into that would often make up most, if not all, the supporting creds you need to get your degree.