The word “liable” points toward a better theory of civil liability. The root of the word lies in the Medieval Latin term ligabilis, meaning to be bound or tied.57 The original idea seems to have been that one who was bound was exposed to whatever might be done to him. According to the Oxford English Dictionary, the term “in older use with wider sense” meant,
“[e]xposed or subject to, or likely to suffer from (something prejudicial).”58 Thus, for example, in Paradise Lost, Milton speaks of how the defeated Satanic hosts recoiled when they were “first with fear surprised and sense of pain” because before their defeat they were “[n]ot liable to fear or flight or pain.”59 They are contrasted in the following lines with the “inviolable saints . . . [i]nvulnerable, impenetrably armed.”60 If one is not liable, one was invulnerable. If one is liable, however, to fear or flight or pain, then one is vulnerable to those things. Notice, that the core meaning of the term
is exposure and vulnerability. The pain suffered by the fallen hosts of heaven is not a duty that they owe or a tax that they are required to pay. Rather, it is the unexpected exposure resulting from a defeat in battle.