President Trump is going back to square one on tax reform. For the champions of his original tax plan — perhaps also for the president himself — this may be disheartening. But for those of us who want a simpler code and lower business and personal tax rates, this is great opportunity to revisit the best principles of tax reform and remind the administration of what not to do.

Former President Barack Obama and Senate Democrats defined tax reform the way Socrates’ wealthy host Polemarchus defined Justice, as a way “to benefit one’s friends and harm one’s enemies.” Health insurance CEOs should pay more than everyone else, and solar panel makers should pay less. Hike the Kochs’ taxes to pay for tax incentives here and there.