Final answer:
Reason is crucial in forming hypotheses, testing them, and drawing conclusions about the world, but its use in morality and faith is complex. Reason can be clouded by emotions or motivated reasoning, and some believe that faith requires beliefs that go beyond rational proof. Reason has its place, but it is not always sufficient in ethical or religious contexts.
Step-by-step explanation:
The question you've asked about why reason should be used sometimes but not others delves into philosophical and ethical considerations. Reason is a powerful tool for humans, enabling us to hypothesize, assess coherence of beliefs, and generate plausible explanations of the world around us. However, the role of reason in morality and religious belief is more complex. Philosophers during the Enlightenment emphasized the use of reason as the grounds for morality, contrasting it with religious doctrines. In this context, reason becomes a way to assert the validity of moral principles independently of religious faith.
Reason and faith often intersect in nuanced ways. Some theologians argue that reason can establish the existence of a supreme being, while others maintain that reason can only partially justify religious belief and full belief requires faith. Furthermore, reason can sometimes be clouded by emotional responses or motivated reasoning, where one's desires influence the acceptance or rejection of evidence. In the case of the sacrifice of Isaac, we see a biblical example of faith potentially conflicting with human reason, indicating that reason is not always the exclusive path to truth.
In summary, while reason is an essential tool for understanding and explaining our world, it is not always appropriate or sufficient for all situations, especially those involving morality, ethics, or faith. This notion is akin to how in scientific reasoning, logic and evidence are used meticulously to test hypotheses and draw conclusions. Likewise, in our personal and societal ethics, we often reason on what is considered 'good' or 'right', with the understanding that these concepts may transcend purely logical reasoning.