How are you judging the validity of an ethical framework? Everything I've read on the subject (which is not a huge amount) assesses ethical systems by constructing intuition-pumping examples (such as the trolley problem, or TORTURE vs. SPECKS, or whatever), and inviting the reader to agree that such-and-such a system gives the right, or the wrong answer to such-and-such an example. But what ethical system produces these judgements, with respect to which other ethical systems are being evaluated?