Final answer:
Trials involving human subjects pose ethical challenges in medicine. Four ethical principles - autonomy, beneficence, nonmaleficence, and justice - guide decision-making in these situations.
Step-by-step explanation:
Trials involving human subjects have historically been a source of difficult ethical issues in the field of medicine. Four main ethical principles can guide our thinking in these situations: autonomy, beneficence, nonmaleficence, and justice. Autonomy refers to the patient's right to make decisions about their own healthcare. Beneficence emphasizes the importance of doing good for the patient. Nonmaleficence focuses on avoiding harm to the patient. And justice involves the fair distribution of healthcare resources.