It seeks peace with its surrounding environment. This is a far different idea from the one I began with when I started to learn about the immune system and assumed—as I suspect many people do—that its chief jobs are to defend and attack. Defend, yes; attack, not necessarily. In fact, the immune system is constantly seeking to maintain harmony, not just by limiting its attacks to all but the most necessary ones, but also by cooperating with the organisms that surround and invade it. At its core, it tries to discern self from other, but having done so, it doesn’t just destroy what is alien.
