If it were not for weapons research, there would be no predator drones or smart bombs or improvised explosive devices or assault rifles. The insurgents in the Middle East and elsewhere would have no means to fight, and there would be no wars, large or small. Even more importantly, there would be no vast arsenals of thermonuclear weapons capable of ending much of the sentient life on the planet. The world would then most certainly be a safer place. The main issue for ethics and weapons research centres on the ethical or moral evaluation of the activity: Is it ever morally justified to design the means to kill, harm and destroy, and if so, under precisely what circumstances?

Purpose The purpose of this paper is to address the topic of the social responsibility and the scientist from a philosophical perspective. This is a (relatively) neglected topic, as philosophers have tended to focus on moral responsibility. Nevertheless, it is important, and timely. Design/methodology/approach Analytical, based on the author’s previous work. This is not an empirical study. Findings That it is essential for scientists to adopt a global outlook with respect to their social responsibilities. This is in (stark) contrast to the conclusion that would be reached for moral responsibility. Research limitations/implications In addition to offering some concrete proposals (see below), a general approach to the question is offered that will be useful for further work. Practical implications Were the suggestions for socially responsible science put into practice, then this would entail a re-orientation of some parts of scientific research; for instance, a moratorium on weapons research. Social implications The long-run social implications of not re-orienting science, for instance not to focus even more effort on climate change, will be negative in the extreme. Originality/value The social responsibility of science has always been important, but it is even more important today. By focussing on global responsibility, this paper offers a new approach.

Weapons research seeks to design new or improved weapons and their ancillary structures. It is argued here that weapons research is both morally wrong and morally unjustified. This ‘case against weapons research' requires lengthy discussion and the argument given here is a summary of that discussion. The central claim is that the ‘standard justification; for all forms of weapons acquisition and deployment, which appeals to defense and deterrence, does not stand up for weapons research because the harms caused by the latter projects into the future in unknowable ways. Weapons research produces practical knowledge in the form of designs for the means to harm, and its practitioners cannot know how this knowledge will be used in the future.

The best‐known example of weapons research and development (WRD) is the Manhattan Project, which produced the first three nuclear weapons and the only ones to have been used in wartime. This project made use of recent discoveries in nuclear physics; however, if WRD is defined as a species of applied science, then it becomes a relatively recent endeavor and much else that should be included under the heading will be ruled out. A definition of WRD such as the following is therefore recommended: WRD is research and development aimed at the design of new weapons, improvements of existing weapons, or the design and improvement of ancillary and support structures. WRD in this general sense, as opposed to specific examples of WRD directed toward particular weapons such as weapons of mass destruction, is a neglected but important topic in applied ethics. It is the focus of attention here, with one exception: autonomous weapons will be discussed, as these are of current interest. Given that WRD produces new ways to kill and destroy, it is evidently a morally questionable activity. The main issue to be addressed is how WRD might be justified.

It is a truism that the side with the better weapons will win a battle and a war, all other things being equal. And it is probably true that the side whose ordinary soldiers, the infantry, have better weapons will win, though heavy weapons can be decisive (as they were at Syracuse and at Sedan 2,000 years later). In this chapter I will consider three episodes from the history of the firearm, the weapon that has been the standard equipment of the ordinary soldier and his platoon of comrades. The first firearms were wildly inaccurate and did not replace other infantry weapons for several hundred years after their introduction. The situation is completely different now, with the infantryman usually being equipped with a deadly assault rifle, an accurate, sturdy weapon that can be set to fire in single-shot, semi-automatic or automatic mode, and so simple to use that a child can (and children do) operate it. I will discuss three weapons designers in this chapter, men who were responsible for one of the first really effective rifles, the machine gun and the assault rifle respectively. We have much more information about these people, and about who used their weapons, than we do for the catapult, as is to be expected. It is also important to remember that these were innovations that were part of the long evolution of the infantry weapon, innovations that were spawned by earlier work, one building upon another – we see the evolution view of technology at work again. I will also say something about the infantry weapons which proceeded those that appeared in the nineteenth century.