Final answer:
Consequentialism is the philosophical school where the morality of an act is judged by its consequences. Utilitarianism is a form of consequentialism that considers the results of an action to be the only criterion of its moral value, distinguishing it from deontological and virtue ethics approaches.
Step-by-step explanation:
The philosophical and ethical school that determines the morality of an act by the consequences of the action is known as consequentialism. In this approach, an action is deemed right if it produces the greatest amount of good, such as happiness or overall welfare. Among the consequentialist theories, utilitarianism is prominent, positing that the results of an act are the sole determinant of its moral worth. An action's rightness is assessed based on the balance of its positive outcomes over negative ones.
Consequentialist thinking differs markedly from that of deontological ethics, which evaluates moral actions based on adherence to rules or duties rather than outcomes. Granted, some deontologists such as W. D. Ross acknowledge that consequences have a role in moral consideration, stressing a balanced view that incorporates both duty and consequences. Conversely, virtue ethics focuses on the character traits or dispositions from which right actions flow, emphasizing the development of good moral character over specific actions or consequences.
In sum, consequentialism, with utilitarianism as a key example, is the ethical theory where the morality of an act is primarily determined by its consequences.