There are many ways of measuring the importance of a scientific discipline, and most would lead you to dismiss synthetic biology as a pretty marginal affair. It has yet to produce a profusion of great papers, to underpin vibrant new businesses, to generate stereotypes in the public imagination, to benefit from vast flows of grant money, or to boast a substantial body of practitioners united in their vision for their field. And a large element of the community can fit into a small lecture theatre, as it did last week at the Synthetic Biology 2.0 conference at the University of California, Berkeley (see page 388).

But some indicators speak differently. To participate in the meeting was to witness an inspiring interdisciplinary festival of ideas — and the central one of supplementing biology's attempts to understand ‘life as it is’ with systematic explorations of ‘life as it could be’ has undeniable élan. The field has attracted venture capitalists, Nobel laureates, acres of newsprint and Craig Venter (although there are some who would dispute whether any or all of these correlate with true worth).

Synthetic biology is also important enough to have attracted enmity. The Berkeley meeting was greeted by an open letter from 35 groups, claiming standing in 60 countries, that denounced the ambitions of synthetic biology and objected to the idea that its practitioners might institute structures of self-governance to mitigate some of its inherent risks — an idea mooted before the meeting, but one that remains an aspiration rather than a fixed intention.

The most powerful of the field's intellectual attractions is its bottom-up nature. Previous attempts to alter or improve on nature have been top-down, starting off with a whole, functioning organism and tweaking it, whether through selective breeding, by the addition of transgenes, or with a vaccine to focus the immune system. But in the light of the emerging technological possibilities of gene synthesis, synthetic biology aspires to work from the bottom up, building things from scratch, to remake, rather than reshape, the world, starting with a blank sheet of paper.

Blank sheets of paper are, for most of us, rather scary. The currently ill-defined and potentially immense capacities of synthetic biology bring worries aplenty, from unintended consequences to deliberate malfeasance. One does not have to agree with the letter's authors to think that, despite offering the possibilities of great benefit, synthetic biology also raises some very significant concerns.

Scientists who are keen to discuss the issues with the world are part of the solution, not part of the problem.

So although many of the specific issues raised in the open letter fail to compel agreement, the overall message that there are real concerns is a valid one. What seems less defensible is the letter's hostility to self-governance; its authors are, after all, keen that the issues be discussed, and implicitly that governance be exercised.

Self-governance need not and should not be exclusive — it does not preclude other forms of governance, any more than the possession of conscience makes redundant the strictures of law. It is hard not to suspect that the problem with self-governance from the point of view of the letter-writers is that it could go some way to addressing potential problems that would make good campaigning issues.

The ability of human societies to modify and transform biological systems will increase more in this century than it has in the hundred centuries since the dawn of agriculture, regardless of whether the transformation unfolds under the rubric of ‘synthetic biology’. Or, at least, we must hope that it will — as the only credible alternative is a future in which massive social upheaval, armed conflict or natural disaster halts the progress of scientific knowledge. The challenge is to foster a matching, or at least sufficient, increase in the wisdom and accountability with which these abilities are used.

That challenge will require changes in the law and customs, in ideology and theology, and in education and economics. No scientific community can be expected to shoulder all that on its own, and nor should it. Scientists who are alive to the possibilities of change, anxious to keep their house in order and be seen to be doing so, and keen to discuss the issues with the world, are part of the solution, not part of the problem.