You've stated the heart of the matter...

and deftly turned aside the "so you're going to let three-year olds play with knives?" objection to age-based criteria for working, voting, signing contracts -- not to mention downing a tumbler of properly aged bourbon. The correct criterion is competency -- sometimes correlated with age; sometimes not. Can the person read and understand a paragraph of unadorned prose on monetary and fiscal policy? Let him or her vote. Can the person be reasonably expected to honor the terms of an agreement? Then let him or her sign a contract and hold him or her accountable if he or she violates the terms thereof. Can he distinguish between Knob Creek and Kentucky Tavern and explain why the risk of a hangover is acceptable from too much of the former but not worth it when downing the latter? Let him drink! (I'm not sure about females; they just don't seem to have the palates necessary to differentiate good whiskey from rotgut.) The trick lies in who has the power to determine competency. The Supreme Court of the United States? The Office of the Speaker of the House? The Democratic National Committee? The Knesset? The EU's College of Commissioners? Yikes! So we're back to the fundamentals of politics -- quis custodiet ipsos cutodes and all that. Personally, I favor panels of continent BLs determining competency, at least as far as young males are concerned (with input from fathers dutifully noted) and groups of nuns in severe habits performing the same function for girls. SR