A lot of legal argument consists of mastering the reasons for and against various recurring dualisms in the law. For example, there is the well-worn dichotomy between rules and standards. Rules provide ex ante certainty and easy resolution of disputes ex post. Standards reduce the incentives for parties to engage in undesirable but rule-skirting behavior ex ante and provide greater substantive fairness ex post. Another example is substance vs. procedure. For example, in administrative or corporate law should judges scrutinize the substance of the decisions that were made, or should they confine themselves to looking only at the procedures used to reach the decision?
A key to understanding the U.C.C., and with it commercial law, is another distinction that students have a harder time wrapping their minds around. I call it the divide between realism and nominalism. During the middle ages scholastic philosophers debated whether or not universals had actual existence independent of any particular instance of the universal, or whether ultimately all that existed was the particulars themselves. The U.C.C. makes a lot more sense, I believe, once you recognize that it in so far as it is possible, it is aggressively committed to nominalism.