Egerton v. Brownlow, (1853) 4 HLC 121 : 10 ER 359, 408, Parke B. " `Public policy' is a vague and unsatisfactory term, and calculated to lead to uncertainty and error, when applied to the decision of legal rights; it is capable of being understood in different senses; it may, and does, in its ordinary sense, mean `political expedience' or that which is best for the common good of the community