Specificity of desired career in statements of purpose

[pubpol101]

I'm hoping to apply to Princeton's WWS immediately after undergrad, and I was wondering if the objectives for my career should be very specific, given (or in spite of) my lack of full-time work. Right now, my personal statement covers the following topics in order: 1) my background and my impact 2) the moral issues with uncertainty in public policy 3) briefly, the fact that graduate school would reconcile the issues between the desire to make an impact and moral issues of uncertainty and 4) specific aspects of the school that I find appealing. The specific aspects of the school go over a range of areas in addition to campus life (quantitative methods, IR, etc.).

While obviously I can't post my SOP here, I was wondering if any of you might think that the SOP would come off as aimless or immature. I had read a successful SOP for Ford, which did not specify any career objectives--it simply focused on the fact that the individual wants to rectify "all of the injustices"--, but I'd like your feedback on this broad outline here.