One aspect of Edward Snowden's revelations in the Guardian about the NSA's surveillance activities has received less attention than it should. The algorithms that extract highly specific information from an otherwise impenetrable amount of data have been conceived and built by flesh and blood, engineers with highly sophisticated technical knowledge. Did they know the use to which their algorithms would be put? If not, should they have been mindful of the potential for misuse? Either way, should they be held partly responsible or were they just "doing their job"?

One could ask similar questions about engineers who build technologies of violence. Although in the west, we use the euphemism "defence" – and weapons often do serve this purpose – arms are just as likely to be used for furthering less-than-honourable goals, whether invading other countries, bombing rebellious populations or staging coups against democratically-elected governments. Engineers who see themselves as builders of the shelter and infrastructure for human needs also use their expertise in order to destroy and kill more efficiently.

When doctors or nurses use their knowledge of anatomy in order to torture or conduct medical experiments on helpless subjects, we are rightly outraged. Why doesn't society seem to apply the same standards to engineers? There is more than one answer to the question of course, but two points are especially pertinent: the common good we engineers see ourselves serving and our relationship to authority.

Health is an unambiguously positive social good that gives the medical profession a strong moral purpose. The same can be said of justice for practitioners of the law. Lawyers and doctors are expected to act in a particular way and, sometimes, to become the custodians of the social good their respective professions embody. Whether they do or not is a different matter.

Technology as a means of social progress is arguably the common good that engineers pursue. Modern engineering emerged in the 19th century, an age when technology was seen in almost unequivocally positive light. Engineers were to "[direct] the great sources of power in nature for the use and convenience of man", in the exultant words of the UK Institution of Engineers, written in 1828. The two World Wars, the gas chambers, the atomic bombs and agent Orange – the awfully destructive scope of technology – were yet to come.

Today, our profession seems to have preserved the sense that technology is almost by necessity a force for good. We are focused on the technical and managerial sides of technology – how to design algorithms; how to build machines – but not so much on the context of its deployment or its unintended consequences. We are not very interested in the politics and social dynamics.

Engineers need the resources of government and industry to do their work, far more than doctors do. Sometimes we are hired for a specific project, but more often, we sell our services wholesale as paid employees. We do not make weapons for a specific war or algorithms for a specific surveillance activity. As a result, engineers who build these devices usually operate at one remove from the consequences of their actions.

In the US, freelance consultant engineers – who appear to have controlled the American Society of Civil Engineers in the late 19th century, and created a strong and autonomous professional identity – were swept away by a corporate model in which most engineers became paid employees of industry. Today, engineering in the English-speaking world largely sees itself as a tool of industry. There are many advantages to this of course, including more resources at our disposal to do our work. But one major drawback is that engineers, as a result, have far less intellectual and practical autonomy than they should.

Our ethics have become mostly technical: how to design properly, how to not cut corners, how to serve our clients well. We work hard to prevent failure of the systems we build, but only in relation to what these systems are meant to do, rather than the way they might actually be utilised, or whether they should have been built at all. We are not amoral, far from it; it's just that we have steered ourselves into a place where our morality has a smaller scope.

There have been encouraging attempts in the engineering profession aiming for a bigger, less reductionist vision of engineering: some mission statements have been written, codes of ethics redrafted and engineering curricula redesigned. However, we are still essentially producing what industry requires: engineers able to carry out technically complex projects, rather than professionals with an in-depth understanding of the social complexity of technology. In fact, we need both. We have very little appetite for engaging with social and political sciences that have something valuable (and sometimes unpleasant) to say about science and technology, including the roles, prejudices and vested interests of scientists and engineers. The cultural shift has simply not happened.

Engineers have, in many ways, built the modern world and helped improve the lives of many. Of this, we are rightfully proud. What's more, only a very small minority of engineers is in the business of making weapons or privacy-invading algorithms. However, we are part and parcel of industrial modernity with all its might, advantages and flaws, and we we therefore contribute to human suffering as well as flourishing.

While there are no easy answers to the questions raised here, we can certainly do better. We can claim, and live up to, our role as social custodians of technology, conscious of its strengths and dangers, capable of navigating its technical, ecological, political and social dimensions alike – even if this might require more years of study for engineering University degrees.

John Rogers, a materials engineer at the University of Illinois, Urbana-Champaign, invented a brilliant epidermal electronic medical device and reported it in the journal Science. In a recent feature article about him in the New Yorker magazine, he was asked whether his invention is for the better or whether it will turn us into soulless robots. His answer was:

[P]eople should think about it. But I'm just an engineer, basically.

It will be a bright day for our profession when we start producing more engineers who, while just as smart as Rogers, have the will and the intellectual capacity to engage with bigger questions about the ethics, politics and social ramifications of their inventions.

Author's note: the opinions expressed in this article are his own and not those of the University of Sydney.