The current debates over the Lisbon treaty and Nama address issues of vital importance to the future of the country, but at the same time raise other fundamental questions about society, democracy and citizenship.

In the aftermath of the first vote on the Lisbon treaty, those on the 'No' side of the debate moved quickly to defuse any possibility of a second 'undemocratic' referendum. The people had spoken, they said, and there was no going back.

Interestingly, however, immediately after the vote, the European Commission requested that Gallup conduct a 'flash poll' of the Irish electorate to determine the reasons underpinning the rejection. Their analysis revealed that one reason had been more important for the 'No' side than any of the usual presumed concerns such as the retention of an Irish commissioner. Twenty two per cent of those polled stated they had voted against the referendum proposal because they did "not know enough about the treaty and would not want to vote for something [they were] not familiar with". The people had spoken all right. Unfortunately, a significant number of them had done so from a position of seemingly wilful ignorance. Why they did not take the time to familiarise themselves with the issues, and what this might mean for our understanding of ourselves as citizens, are interesting questions.

Looked at in a different light, the number of 'No' voters citing lack of familiarity with the treaty as their motivating reason amounted to a depressingly small minority. What was truly undemocratic about the whole debacle was that the consensus opinion of 27 democratic governments representing 500 million people could be swept aside by a refusenik group constituting about 0.04% of the European population – a group who, by their own admission, cast a vote while being wholly unaware of the treaty's contents. This was less a triumph of democracy for the voters of a ruggedly independent state, and more a triumph of ignorance in the face of reason, rationality and responsibility.

Public discourse on Nama is illuminating in a similar vein. Commentators were quick to remark that a recent poll on the Nama proposal showing "only 26%" public support indicated majority opposition to the plan. But in the same poll only a minority – 36% of respondents – expressed support for bank nationalisation, the only politically realistic alternative short of letting the banks go bust. On the polling figures, public opinion would seem to favour neither one option nor the other.

Whatever about the specific merits or demerits of Nama itself, something must be done to fix the banks and recent calls by the likes of Sinn Féin to put the Nama legislation to a referendum are misguided and unhelpful. While it would be nice to think that a vote on Nama would be decided on the merits, the Lisbon experience must give us pause. In a two-horse race, placing your money on 'neither' is a sure-fire way to lose. Sometimes leadership trumps public opinion, and it is not undemocratic for our elected representatives to lead. Protest-voting, while it may, perhaps, be justifiable, is no way to run a country.

There are parallels here with the public attitudes reported in Britain during the MPs' expenses scandal. Vox pops asking people which MPs they thought should resign met frequently similar responses: "All of them". All were tarnished with the same brush and many of those polled seemed to reject the political system, the very idea of politics, in its entirety.

Such political rejectionism contributes nothing of value to public debate and ignores the necessity of governance and of decision-making. It goes hand in hand with the attitudes of those who vote defiantly, and fatuously, on the basis of ignorance and amounts to a wholesale abnegation of the responsibilities we have as citizens of this republic. Michael D Higgins recently called for a renewed debate on the idea of citizenship, an idea he says has been absent in recent times from state approaches to the organisation of society.

Citizenship, however, amounts not merely to a collection of rights afforded by the state to individuals. It also entails a set of responsibilities to our fellow citizens. One such responsibility is to acknowledge that, through the ballot box, we each have the power to determine the other's future.

Perhaps it is the absence of this sense of responsibility to others, or of solidarity with our fellow European citizens, that contributed to the outcome of the first Lisbon referendum. Not so much a case of 'If you don't know, vote No' but more so 'If you don't know what's in it for you, vote No'. A renewed sense of what citizenship entails points to a better maxim for those disengaged from public debate as the second referendum approaches – 'If you don't know don't vote' – while also raising a serious question: 'Why don't you know?'

Vigorous debate on both Lisbon and Nama is to be encouraged. But political rejectionism stymies that debate while offering nothing constructive. How we hope to overcome that and to renew our understanding of what it means to be a citizen arguably poses a political challenge of equal, if not greater, importance.

Owen Corrigan is researching his PhD thesis on citizenship and social policy at Trinity College Dublin

David Kenny is on leave