Defence
The standard justification of weapons design was introduced in Chapter 1. Here, defence as a justification of weapons design is considered in terms of the notion of a defensive weapon, the idea being that the design of defensive weapons needs no (further) justification because (self-)defence is always morally permissible. The position is criticised. This entails a discussion of the idea of defence, of levels of defence, of defence and aggression, and of the idea that there can be weapons that cannot aid aggression. It is established that no weapons fall into the latter category and, hence, that justification of weapons design in terms of defence must make reference to the actual historical context in which its products are employed. The author calls this an historical justification.