  In Cockburn’s third and last philosophical work, the Remarks upon the Principles and Reasonings of Dr. Rutherforth’s Essay, she answers Dr. Thomas Rutherforth, a critic of Clarke’s fitness theory. Rutherforth himself offers a brand of consequentialism, defining as moral goodness that which brings about good and prevents evil. Cockburn objects to this view, arguing that it ignores the underlying fitness relations that serve to define what harms and benefits are significant or relevant for human beings in particular circumstances. Even a hermit or someone stranded on a deserted island may possess a sense of virtue, Cockburn argues, since virtue is not founded on our prediction of the effects our actions will have on other people. On Cockburn’s view, humans have a natural and innate tendency toward what is good and benevolent that transcends merely weighing the effects of one’s actions. Cockburn identifies the moral sense as being a source of this disinterested affection essential to moral decision-making.  While reason retains its position of prominence in her morality, the moral sense plays an important role according to her in motivating agents to act morally. The obligation we feel to obey moral rules arises, for Cockburn, not from reason alone, but from the perceptions of natural conscience, or moral sense. The moral sense, if governed by the “natural perceptions of the understanding,” ought to influence our actions – it is a necessary component in creating moral obligation.