The Concept of Necessity

I'm interested in the concept of necessity because we were talking about, you define cruelty quite well. But there's a question of kind of how far we take that. I think it's reasonable to say that when you say you need to be healthy, what we mean is that everybody has such a strong and justifiable desire to live a healthy life. So would that kind of thing fall under your conception of necessity? Like should someone be able to buy hay fever tablets, which not only contain lactose, but also will have been tested on at least two other mammals under UK law? That's a good question. For something like that, it's very hard. And for something like that