Politics is perhaps the most vulnerable of all professions to low public esteem. But while the fact of the low esteem in which it is held is often adverted to, the fundamental reasons for this vulnerability are rarely addressed in any depth, either by politicians or by those who write about the subject.
This fundamental reason is, I believe, that all politicians in office have to take - or if on the back-benches of a government party have to accept responsibility for - an extraordinarily wide range of decisions that affect the lives of the whole community. If they are on the back benches of a government party they have to accept responsibility for those decisions.
And many such decisions, if made in the general public interest, are bound to have negative effects upon the popularity of those politicians with many individuals and groups which, at intervals of five years or less - on average three years in this country - have the power to dismiss them from office, and even from their careers as members of parliament.
Of course, other careers involve taking many difficult decisions: judges face this all the time. But judges have security of tenure, and so do clergy, at least of the Roman Catholic and Anglican Churches. In both cases this security is designed to enable them to act and speak without fear or favour.
It is, however, the combination of a huge number of decisions to be taken on the one hand, with a total absence of any security of tenure that makes politics such an extraordinarily demanding career, demanding not just in terms of the work-load, but also morally.
It means that politicians face a much larger number of moral dilemmas than people in other professions. They are constantly faced with choices between doing what they know or believe to be the right thing, or avoiding or delaying such a decision because they know that such action will lose them votes at the next election.
I have to say that I have always been very conscious of this aspect of politics.
My own motivation in entering politics 35 years ago derived, of course, mainly from practical concerns about such issues as defective economic policies that were then inhibiting growth, failure to address social disadvantage, irredentist attitudes to Northern Ireland, and concern to advance European integration.
But I was also conscious of the challenge posed by the huge widening of moral choices that I knew political life would entail: the constant dilemma between doing what is right and what is popular, and the resultant test of one's capacity to steer a judicious course between these two choices. I say "judicious course", because realistically, doing "the right thing" on every occasion, however small the issue, would be to condemn oneself to a short, and consequently worthless and unproductive, political career. On the other hand, to fall into the trap of perpetually seeking to be popular would be equally worthless and unproductive, a complete waste of one's life.
The moral challenge in politics is to balance these two choices in a constructive but realistic way. That, indeed, is what democratic politics is about.
The true test of a politician is whether, without in the process being persistently defeated at the polls or losing his or her own seat - thus undermining or even destroying the possibility of doing further good - he or she succeeds in combining principle and prudence in such a way that, over time, the right decisions are made.
Looking back on it all, I suppose that the fact that, when in my teens I first contemplated an eventual career, I was stimulated by this moral-choice aspect of politics, derived partly from growing up during the war years and observing the terrible choices that political leaders had to make in wartime. And, for family reasons, I was also drawn to reflect upon the moral challenges that the founders of our State had had to face during the War of Independence and the Civil War.
Beside those kind of hugely difficult moral decisions, the choices I was likely to face in politics were going to be tame indeed, but would still offer far more of a challenge than I was likely to face in any other career open to me in the second half of my working life.
What bothers me is that none of this moral-challenge aspect of politics seems to enter the heads of most people who write or talk about the subject. They often make it sound so easy.
When civics is taught in our schools this whole issue should, I feel, be given a prominent place. Only if each new generation is brought to see and to understand something of the uniquely morally demanding nature of democratic politics will democracy endure.
Then, perhaps, a few young people in each new generation may in turn be inspired to try their hand at this demanding career, instead of - as seems to be the case with so many today - dismissing it out of hand as simply a dodgy and disreputable way of earning a living.
But something else is also needed if democratic politics is to be kept alive and well. Politicians will also have to clean up their act. When even a small minority of them conspicuously betray their trust, abusing their role in society for their own personal financial advantage, public attitudes to the whole corpus of politicians can become very negative indeed.
For this has obscured the fact that in the part of Europe to which we belong, all but a handful of politicians are in fact free of any taint of financial corruption.
But it has to be said that the honest majority of politicians here has shown a lack of alertness to the temptations posed to a small minority of their colleagues by the interaction of business and politics under the conditions of modern capitalism. We live in a world where governments have a major job in controlling negative aspects of the capitalist system. Small changes in tax or planning laws can have huge financial repercussions. We no longer live in the relatively innocent world our parents inhabited.
The risks of close links between business - some elements of which can be quite unscrupulous - and politics are now huge. Politics and politicians now need to be sealed off from that world to an extent that was not necessary in the past.
In Ireland we have recently gone some way towards this objective. But we have been unwilling so far to take the final, necessary step of restricting financial contributions to political parties and politicians to quite nominal amounts, and by tightly restricting spending by political parties.
It is time this final step was taken. No convincing reason has been put forward by any politician as to why this has not been done.