A lot of people who study Law at University do so because they want to become practising lawyers, whether as barristers or solicitors, but it is not necessary to read Law at University to become a practising lawyer. Equally, studying Law at University is a legitimate subject for academic study even if you definitely do not want to become a lawyer or think that you may not become a practising lawyer. That is because the study of Law at University is not a vocational subject; it is an academic subject and an intellectual discipline.
Graham Virgo, Professor of English Private Law and Deputy Chair of the Law Faculty Board at the University of Cambridge, discusses the benefits of studying a law degree even if you do not wish to progress into the legal professions. Considerations include training the student to think and write logically and clearly; enabling the student to engage in the critical analysis; enabling the student to engage in a wide variety of different academic disciplines; and because the subject is interesting and intellectually stimulating.
For more information about studying a Law degree at the University of Cambridge, see http://www.law.cam.ac.uk/admissions/