Answer:
The correct answer is: We should think the hardest about the beliefs that we care about the most deeply.
The statement "The cognitive and the emotional are combined in philosophy" implies that philosophy requires both rational analysis and emotional awareness. Therefore, we cannot rely solely on reason or emotion to guide us when we do philosophy. Rather, we must consider the interaction between these two aspects of our thinking, and reflect on how our emotions may influence our beliefs and reasoning. In other words, we should be especially careful and critical when examining beliefs that we hold dear, and recognize the role that emotions can play in shaping our views.