On the one hand, knowledge is a necessary condition, and perhaps a con stitutive feature, of technologies, such as communication and information technology, that contribute greatly to individual and collective wellbeing. Consider, for example, the Internet. So evidently technological knowledge is a good thing and ignorance of it a bad thing. On the other hand, some tech nologies at least, e.g., nuclear technology, can be extremely harmful to indi viduals and collectives. Consider, for example, the atomic bombs dropped on Hiroshima and Nagasaki. So, at least with respect to some technologies, evidently knowledge is a bad thing and ignorance a good thing. Accord ingly, the question arises as to whether we ought to aim at ignorance, rather than knowledge, of certain technologies and, if so, which technologies.