That individuals can be harmed without knowing it has important implications for the proper assessment of the treatment of animals. Modern farms (so-called factory farms), for example, raise animals in unnatural conditions. The animals frequently are crowded together, as in the case of hogs, or kept in isolation, as in the case of veal calves. Since the only environments these animals ever see are the artificial ones in which they live, it sometimes is claimed that they don't know what they are missing and so cannot be worse off for having to forego [sic] an alternative environment they know nothing about. The unspoken assumption is not that what you don't know can't hurt you; it is that what you don't know can't harm you. This assumption is false. If I were to raise my son in a comfortable cage, in isolation from other human contact, though seeing to it that his basic biological needs were satisfied, and if, in all of my dealings with him, I went to considerable trouble to insure [sic] that he experienced no unnecessary pain, then I could not be faulted on the grounds that I was hurting him. However, I would have quite obviously harmed him and this in a most grievous way. How lame would be my retort that my son "didn't know what he was missing" and so wasn't harmed by me. That he doesn't know what he's missing is part of the harm I have done to him. Those animals who are raised intensively, then, let us assume, do not know what they're missing. But that does not show that they are not being harmed by the conditions under which they live. Quite the contrary, just as would be true in the case of my son, what we should say is that part of the harm done to these animals by factory farming is that they do not know this.