A Conservative prime minister - Robert Peel - once condemned public opinion as a compound of folly, weakness, prejudice, wrong feeling, obstinacy and newspaper paragraphs.
Such a view did not stop the pollsters in their tracks, however. And today, one of the favourite topics to quiz the public about is the NHS.
Whole newspaper stories are built around the findings from opinion polls. The general 'message' that seems to emerge from polling on the NHS is that - as Private Frazer from Dad's Army would have intoned - We are all doomed.
But asking the public what they think about the future of the NHS is a tricky business. Some polls confuse the normative with the positive in their questioning, for example.
So, what the public would like to see happen and what they think will happen can be very different.
Generally, many polls report a pessimism about the future of the NHS.
Such results can be, and have been, interpreted as support for scrapping the NHS and moving to some other system.
But these views may simply reflect a pessimism about politics and a degree of powerlessness: will those in charge really listen to me?
Whether or not those in charge are listening, it has been pointed out that questions about satisfaction with the NHS are often answered as if the question asked had been: are you satisfied with the government?
Confusion about what question is actually being answered can be compounded by a fundamental difficulty concerning the source of the public's opinion, or rather how opinions or views are arrived at.
%Many polls about the NHS ask some extremely difficult questions which are not exclusively about 'opinion' (ie subjective) but also involve factual knowledge or evidence, for example. So, asking whether the NHS should change its funding system from general taxation to social insurance presumes a knowledge of what these forms of funding are (plus their variants), and what the research evidence shows as far as the impact these forms of funding have on equity, efficiency, organisation and so on.
Without that knowledge, it is difficult to attach any worth to public opinion.
Interestingly, a consistent finding from opinion polls is that the main source of the public's health and healthcare knowledge is gleaned from the media.
Given the media's promulgation of healthcare stories based on opinion polls, there would seem to be an unintentional circularity of thought at work: stories about opinions help form opinions which are then surveyed and reported. . .
Some of this touches on the new task for NHS providers to survey their patients for views about standards of care received.
While questions can be carefully designed to concentrate on factual experience (how long did you wait? ) in order to make it worth while asking such questions in the first place, at some point a judgement has to be made by someone about whether a certain experience (for example, waiting over six months to see a specialist) is acceptable or not.
There is no escaping opinion in the end. A problematic task for the NHS is how it reacts to public opinion so as not to undermine its essentially collective features as a public service.
John Appleby is director of the health systems programme at the King's Fund.