Rationalism characterizes a wide range of philosophical topics.

• How do we know who and what we are? Rationalists claim the self is known through rational intuition, while the empiricist thinks that the unity of the self is illusory.
• What is the nature of cause and effect? Rationalists claim casual links are known through reason. The empiricist replies that it is because of habit that we know, for example, that a fire is hot.
• How do we know which actions are ethically correct? Kant argued that ethical worth could only be understood from a rational perspective. Moral evaluation takes place when rational agents consider their actions under hypothetical conditions.