Post-print copy, 2014 Biosecurity and Open‐Source Biology: The Promise and Peril of Distributed Synthetic Biological Technologies 1 Nicholas G. Evans and Michael J. Selgelid Introduction Science is open to the degree that scientific information is freely available and/or easily accessible to interested parties. Other things being equal, this means science is more open to the degree that there is a lack of restrictions on, or interference with, information dissemination; and science is more open to the degree that there are no expenses associated with, or barriers to, access to information. A laboratory may not deliberately exclude outsiders, for example, even though hard copies of laboratory notebooks are difficult to access; online academic journals may be open to any interested party, but only if that party can pay. A degree of openness is an important feature of scientific practice, enabling researchers to share results and conclusions, reproduce experiments, and submit critiques of experiments. Scientific knowledge has long been considered integral to human health, wealth, and security (Bush, 1945). Links between scientific openness, knowledge-building, and innovation are particularly strong in the twenty-first century, as online communication enables information sharing and distribution on an unprecedented scale. When the use of science and technology poses certain dangers—such as the risk of nuclear warfare— scientists sometimes accept restrictions on freedoms and limitations to openness in order to promote security (Westwick, 2000). The trade-offs that are acceptable to scientists in achieving this security, however, are determined in part by the organization of a field. Physicists, informed by and embedded in national security frameworks during the Second World War, were primed to accept a modicum of 1 This is a post‐print copy of “Biosecurity and Open‐Source Biology: The Promise and Peril of Distributed Synthetic Biological Technologies,” published online in Science and Engineering Ethics, 2014 DOI 10.1007/s11948‐014‐9591‐3. This version is archived on the lead author’s personal website; the published version can be found at http://www.springer.com/‐/7/OeVQNqzRRqiQp7n3E7EdsA