The professions exist because they help us to solve problems that we do not have the expertise or the time to handle ourselves. Yet there are now systems that can do much of this without human experts. As these machines are becoming increasingly capable, now is a good time to ask whether the traditional professions that evolved to solve our problems in the 20th century are fit for purpose in the 21st.

Traditionally, we have trusted doctors to keep us in good health, teachers to educate our children, lawyers to advise us on our entitlements and accountants to manage our finances. They have had knowledge and experience that lay people did not.

Yet this tradition is under siege. Last year, almost 48 million Americans used online tax preparation software rather than human tax professionals to file their tax returns. It is said that the best-known legal brand in the US is not a traditional law firm but legalzoom.com, an online legal advice and document drafting service. Associated Press and Forbes both use algorithms to write earnings reports and sports commentary that until recently would have been handcrafted. At WikiHouse, an online community designed a house that was “printed” and assembled for less than £50,000 in the UK.

In The Future of the Professions, Richard Susskind and I explore these and similar changes that we have observed in professional work. We identify two futures for the professions, both of which rest upon technology. The first is within the comfort zone of most professionals. It is a more efficient version of what we have today. Professionals use new systems to help them work in the traditional way – software is used, for example, by accountants to perform difficult computations and by engineers to design more complex buildings.

But the second future is very different – the introduction of a range of increasingly capable systems will entirely replace the work of traditional professionals.

For now, these two futures will develop in parallel. But in the long run the second future will dominate. It will give rise to new ways of sharing expertise in society and will lead to the gradual dismantling of the traditional professions. This is where the latest evidence and thinking leads us.

An important question follows – what should our attitude be towards these changes? Do we encourage them or resist? Should we constrain the march of technology across the professions? What future should we want? We should not rush to answer. The professions are at the heart of our social and economic lives. They are responsible for some of the most important functions in society.

Our view is that it is precisely the importance of the work that professionals do that should lead us to embrace radical change. The traditional professions are creaking. Affordable access to good quality medical guidance and legal support, for example, is woefully low. There are similar problems across other professions. The promise of new systems and machines that can, say, diagnose illnesses, offer legal advice and teach our children, is a liberation of the expertise that was previously locked up in the heads of professionals or buried in their textbooks and filing cabinets.

We expect that many people will find this uncomfortable. The idea that the traditional professions will play a less prominent role in the future will be troubling. In our book, we discuss many common anxieties and objections. Among them, however, are three underlying mistakes.

New systems can undertake an increasing number of tasks more efficiently and affordably than humans

The first mistake is to reject the idea that professional work, unlike “simpler” types of work, can in fact be computerised. This is often based on the belief that professional work is too rarefied or “complex” to be performed by a machine.

This is wrong for two reasons. First, it treats professional work as an indivisible and uniformly complicated lump of activity. In fact, when professional work is broken down into its constituent tasks, a great many of these turn out not to be so complex after all and can be done by less qualified people with the support of systems, or indeed by machines. The second reason is that it underestimates the capabilities of these new systems, which can undertake an increasing number of tasks more efficiently and affordably, often in very different ways from human beings.

The second mistake is to expect more of these new systems than we expect of ourselves. A good example of this is the robotic pharmacist installed at the University of California in San Francisco. This robot, it is said, has made 6m prescriptions, only one of which in error. A sceptic might pounce and say that this error is unacceptable. Yet to do so would ignore the fact that human pharmacists, at best, tend to make wrong prescriptions 1% of the time – this would cause not one error, but 60,000.

Salman Khan launched the Khan Academy online educational service in 2006. It is now used by 10 million students each month. Photograph: Martin Godwin/The Guardian

This leads to a related point – often, in judging the merits of a new system, the appropriate comparison is not with what the best human expert would achieve, but with nothing at all. Consider that every year on eBay, 60m disagreements are resolved using “online dispute resolution” software, without a traditional lawyer. This is three times as many lawsuits as are dealt with in the entire US justice system. Clearly, in the absence of this system many of those 60m would go unresolved. And it is this – what access to expertise people would have if these systems did not exist – that should often be our benchmark.

The third mistake is perhaps the most important. This is to let our admiration for features of the current professions distort our judgment about the different people and systems that might replace them in the future. A classic case of this is the possible loss of “personal interaction”. Many of the illustrations here do not involve face-to-face interaction with a human being (a doctor or a lawyer, for example). Often, critics say that this personal interaction is in fact the most important thing about the professions. Losing this is too high a price to pay for change.

But this cannot be right. That argument suggests that we should stop the 10 million students each month who visit Khan Academy, an online collection of instructional videos and practice problems, from using the system on the grounds that there is no “face-to-face” interaction with a teacher. Similarly for the hundreds of thousands of people who visit legalzoom.com each month.

The purpose of the professions is not to provide people with “personal interaction”. It is to solve problems that people do not have the wherewithal to solve themselves. It just so happened that, in the 20th century, the best way to do this involved face-to-face interaction with other human beings. But in the 21st century, if we find more affordable and accessible ways of doing so, we should embrace them rather than reject them – even if they look very different to the traditional approach.

If we do embrace this future it will not bring about an end to healthcare, law, or accounting. Nor will it end our medical problems, legal disputes or need for tax compliance. But it will allow us to transform the way that we solve these problems and to spread expertise far more widely across society. This is something we should welcome and not resist.

• Richard Susskind and Daniel Susskind’s book, The Future of the Professions, is published by OUP, priced £18.99