As waterboatman says. Gaining a degree in a subject does not tie you to that discipline for the reast of your life, it merely proves to potential employers that you have a certain level of intelligence and the ability to learn. If you watch programmes such as Christmas University Challenge you will notice that a large proportion of the alumni taking part are earning their living doing jobs unrelated to their degree; there a few jobs which require specific qualifications (doctor etc) but most do not. Get the best degree you can which probably means study the subject you enjoy most.