If an act could only be performed because it is morally good, the justification would be circular: the act's goodness presupposes the motive, and the motive presupposes the act's goodness.
Motive(in ethics, as what drives a person to act morally)
The internal reason or desire that makes someone want to do something.
Presupposes(as describing what Plantinga's argument takes for granted)
Assumes something to be true without proving it—like how an argument might presuppose that logic works, without first arguing that logic is valid.
justification(Third condition of the tripartite account of knowledge)
The condition on a knower's belief that excludes mere luck — the belief must be held in a way that is appropriate or warranted, not merely accidentally correct.
According to the Treatise, artificial virtues include justice, fidelity to promises, allegiance to government, and chastity. Hume devotes much discussion to justice, which he treats as a paramount and paradigmatic artificial virtue. Hume understands justice primarily as honesty with respect to property or conformity to conventions of property (T 3.2.2.28). Establishing a system of property allows us to avoid conflict and enjoy the possession and use of various goods. The social value of conventi