Final answer:
John Stuart Mill, a utilitarian philosopher, would consider the overall happiness and benefits for humans when judging animal testing. However, he might also be concerned about the suffering and quality of life experienced by animals.
Step-by-step explanation:
John Stuart Mill, a philosopher known for his utilitarianism theory, would likely approach the testing done on nonhuman animals by considering the overall happiness it produces. Utilitarianism judges actions based on the greatest good for the greatest number of people, so Mill might argue that if animal testing brings about significant benefits for humans, such as the development of life-saving medications, it may be justified. However, Mill's revised account of pleasure also emphasizes higher-quality pleasures, so he might also be concerned about the potential suffering and quality of life experienced by animals used in testing.