Dr Madsen Pirie is President of the Adam Smith Institute.

The word “liberal” has been contaminated in both Britain and the US.

In the US it is used to denote left-wingers, usually Democrats, who favour big government, augmented welfare programmes, and a high degree of central management of the economy and society. “Liberals” are taken to be the opponents of “conservatives.”

In the UK the word was taken by a political party that morphed into the Liberal Democrats, a party that strays far from the original meaning of the word.

Traditionally, “liberal” denoted someone who supported personal freedom and the right of people to make their own decisions about most of the aspects of their life. It included the protection of their right to own property, and the right to decide what degree of risk they were ready to accept in their lifestyle.

In neither the modern US or the UK does the word mean that any more. Freedom has been thought so attractive that people who want to limit it claim to be acting in its name and describe themselves as “liberal.”

Clearly the word has gone beyond recall in both countries, indicating that a new word is needed to denote what it used to mean. The phrase “liberal in the European sense” is sometimes used, but is both awkward and cumbersome. The phrase “classical liberal” is better, but it implies that it belongs to the past rather than being relevant for the present. Hayek’s suggestion of “Old Whig” is even worse in that respect.

At this point the term “neoliberal” enters the stage. Its name does not suggest it belongs to the past. Quite the reverse; it suggests something new, which to some extent it is. The addition of support for free trade, free markets, and economic development to the ideas that revolve around personal freedoms has produced a comparatively recent combination that merits a new name.

Of course the term “neoliberal” has been used as a catch-all insult to denote anything disliked by left-wingers. Indeed, it was so over-used that any original meaning gradually drained from it. A student demanded that Colin Talbot, the University of Manchester’s Professor of Government, be disciplined for describing the term as meaningless. “No-one claims to be a neoliberal,” he remarked.

They do now. In 2015 I published a piece entitled “Looking at the World Through Neoliberal Eyes,” based on a lecture I gave at Brighton University. We followed this up at the Adam Smith Institute with a piece by Sam Bowman, our Executive Director, setting out the basic tenets of neoliberalism, and last October the Institute rebranded itself.

We had previously described ourselves as a “libertarian free market think tank,” but now we have changed it to a “neoliberal free market think tank.”

History has many terms that were originally insults, but which became either simple descriptions or sometimes badges of honour. The Dutch rebels who sought independence from Spain were dismissed as “beggars” (“Les Gueux”) by their Spanish overlords, but proudly accepted the name, with many wearing tiny wooden begging bowls as ornamental pendants. Both “Whig” and “Tory” were originally insults.

Now we take “neoliberal” to denote a set of attitudes and principles that make up that new combination of free markets, free trade, economic development, and a large measure of personal freedoms. If the term was meaningless before, it is no longer so. Today sees the publication of my new book, “The Neoliberal Mind,” which sets out what it represents.

Included in that list is a strong concern for the welfare of the world’s poor. We take pride in the achievements of neoliberal principles over the past few decades. Never in history have such advances been seen in reducing poverty, hunger and starvation, and early death from diseases. These advances have been gained through the application of neoliberal principles onto a world scale.

The left-wing claim that neoliberalism represents the interests of rich people in developed countries could not be further from the truth. The people it benefits most are poor people in developing countries.

Intriguingly the term includes character traits as well as principles. Neoliberals tend strongly to be optimists, ready to accept new technology for the opportunities it will bring rather than fearing it for the changes it portends.

One thing that really separates neoliberalism from the ideologies that oppose it is its strong empirical streak. It is very much a real-world outlook, in which results, rather than theory, constitute the test it sets itself. It is prepared to modify both principles and policy if they fail in practice to achieve the sought-for results. Unlike some ideologies, it judges itself on whether it actually works in practice.

We think it does work, and cite its achievements in lifting up the worldwide condition of humankind as the strongest argument in its favour. It does work and it will continue to work, achieving even more in the future than it has in the past.

Sir Christopher Wren’s epitaph in St Paul’s reads “If you would seek his monument, look around you.” The same can be said of neoliberalism. It you want evidence of its success, look at the world it has engendered. It is not perfect; nothing is; but it is better.