Philosophy offers the opportunity to think about basic human questions-- about personal and social values, about the nature of our minds and ourselves, about the nature of scientific and other kinds of knowledge. Philosophy involves the critical and careful reading, development, and evaluation of arguments, both others and your own. Quite simply, philosophy provides training in critical and constructive thinking, skills that are valuable in any professional field as well as in the rest of your life.
Some of the practical benefits are reflected in exceptional performance by philosophy majors on graduate admissions exams. Studies showed that philosophy majors scored higher than any other group on the verbal sections of the GRE, and much higher than any other humanities majors on the quantitative section. Philosophy majors were second only to math majors on the GMAT, and third only to math and economics majors on the LSAT. Of course, majors' training in philosophy may not be wholly responsible for these results-- it might also be the kinds of students who enter the field. But in either case, the report suggests that you're wise if you join them.
Philosophy has special affinity with the legal profession, in which argument and the application of general rules to cases play central roles. Many law schools recognize this connection, and are especially receptive to philosophy majors. But philosophical skills are valuable elsewhere as well. In business you must be able to formulate and clarify problems, to analyze potential solutions, and defend your approach in a clear and rational way. All these abilities are improved by exercise in philosophical argument. And finally, medical schools place increasing importance on the ability to reflect on the ethical issues that arise in their practice-- and these are problems treated in moral philosophy.
But the most important reasons to study philosophy are not the practical-- the college years should not just be about professional training. They are an opportunity to think about basic human questions and answers that will help guide your life.