> I think the problem is that, much of the time, there's no way to know _if_ someone is planning on causing harm In this case, the judgement was to decide if i

> I think the problem is that, much of the time, there's no way to know _if_ someone is planning on causing harm In this case, the judgement was to decide if it's lawful to make a damp-firework's worth of explosives even if everyone agrees there's no harmful intent, or even any realistic capability to cause harm ("small amounts to produce insignificant detonations"). You can see this in the dissenting judges opinions, where they conclude that it's unlawful when only asking about "personal experimentation or own private education". There is no mention of balancing personal freedom against risks to greater society, or evaluation of whether it might be used for harm, or if the quantities produced could ever cause any real harm to anyone. I find the quoted summary of the dissenting opinion strange: > “to say that something is done for one’s own private education is not a sufficient object for the purposes of the section 4(1) defence, as it does not identify the use to which the explosives will be put in order to provide such education. > “Similarly, personal experimentation is not a sufficient object for this purpose as, although it identifies in very general terms what is to be done with the explosives, it does not identify any purpose for so doing.” Reading that, I can't help thinking that personal experimentation is what is to be done, and private education is the purpose for so doing. But I'm not a judge, and that won't be the whole opinion.