At first glance the question, What is solitary confinement? appears to be rhetorical, if not insulting, but you would be surprised, if not incredulous, how many prison rights activists are at a loss when I pose it to them. Even more perplexing, many prisoners are only able to provide the standard but antiquated response, which is: a prisoner in a cell behind a solid door, in which he/she is isolated from other prisoners and human contact.
