Depending on your view of it, last week was a good or a bad week for parliamentary democracy. Wednesday saw the House conduct the first major personal vote since a John Keyled Government first took office in 2008. While some were surprised at how few MPs voted against the Marriage (Definition of Marriage) Amendment Bill, the rhetoric the Bill's opponents employed in the House was not surprising. Importance was placed on the views of their constituents. Some MPs might consider themselves elected to exercise their judgement on an issue they probably did not campaign on; other MPs consider they must represent the views of their constituents on an issue on they probably did not vote on; and New Zealand First wanted to let the constituents do the voting, by proposing a referendum.

Anyone who tuned in to Parliament TV again on Thursday (perhaps lured back by the 'personal vote in progress' music) was rewarded with the more polarising debate on the alcohol purchase age. This led to the second personal vote in as many days, but one that was much more procedurally complex and probably had viewers wondering if Parliament ever gets anything done if it takes so long just to hold a vote. Of course, most votes are swift and predictable party votes, often arrived at after speeches that attack political parties more than they debate the issue. Personal votes on conscience issues, to use the official phrasing, are rare.

The Law Commission warned against the use of "conscience votes" on broader policy issues regarding alcohol regulation other than the purchase age. Among its reasons was that partybased voting "will also encourage parties to have clearly defined alcohol policies for voters to consider, while facilitating greater policy accountability to the electorate."

There are many views on the democratic accountability of personal votes. Is an electorate MP merely a conduit for his or her constituents, or should they vote their own conscience and use their political leadership to persuade their constituents they are right? In an MMP Parliament, should important or controversial issues only be decided when parties have taken a position to the electorate at the previous election? Or, as New Zealand First advocated, should these issues be exercised by the conscience of the entire electorate, via a referendum?

It is difficult for list MPs to represent the views of their constituents, as their supporters have voted for a party that has probably deliberately avoided taking a position on "conscience issues". National's list MPs split on the Marriage Bill, with 10 in favour and seven against. On the first vote on the alcohol purchase age, six National list MPs voted for keeping it at 18 yearsofage, while 11 voted for the split age or for raising it to 20 years of age. Labour's list MPs were more equally divided, seven voting for 18 yearsofage and five against. These figures may represent the divergence of views among party supporters, but more likely represent the personal views of the list MPs in question.

It can even be hard for electorate MPs to say they are voting based on what their constituents want. The problem with silent majorities is that they never speak up.

Politicians may be the biggest supporters of conscience votes, as they allow debate and progress on important issues without dividing parties or their support base. Supporters of abortion law reform in 1977, homosexual law reform in 1986, civil unions in 2004, and now (unless the numbers change dramatically) samesex marriage, all have the conscience vote to thank for their victories.

Whatever your view on the outcome of the votes or the basis on which MPs voted, it is hard to disagree that last week the quality of parliamentary debate and the public interest in Parliament were greatly improved. That must surely be a good thing.