Engineering
Engineering is the creative application of science, mathematical methods, and empirical evidence to the innovation, design, construction, operation and maintenance of structures, machines, materials, devices, systems, processes, and organizations. The discipline of engineering encompasses a broad range of more specialized fields of engineering, each with a more specific emphasis on particular areas of applied mathematics, applied science, and types of application. See glossary of engineering.
Security
Security is freedom from, or resilience against, potential harm (or other unwanted coercive change) from external forces. Beneficiaries (technically referents) of security may be persons and social groups, objects and institutions, ecosystems, and any other entity or phenomenon vulnerable to unwanted change by its environment.
Engineering
When I looked at the science of engineering and saw that it had disappeared after its ancient heritage, that its masters have perished, and that their memories are now forgotten, I worked my wits and thoughts in secrecy about philosophical shapes and figures, which could move the mind, with effort, from nothingness to being and from idleness to motion. And I arranged these shapes one by one in drawings and explained them
Al-Muradi, The Book of Secrets in the Results of Ideas, 11th century; Translated and cited at leonardo3.net/bookofsecrets/index, 2015
Security
[T]he production of security should, in the interests of the consumers of this intangible commodity, remain subject to the law of free competition. … [N]o government should have the right to prevent another government from going into competition with it, or to require consumers of security to come exclusively to it for this commodity.
Gustave de Molinari, tr. J. Huston McCulloch, §II of The Production of Security (Auburn, AL: Ludwig von Mises Institute, 2009; orig. 1849), pp. 22–23.