Final answer:
Thomas Aquinas posits that humans have practical reason to understand natural laws and divine reason provided by revelation. These types of reason allow human beings to align human laws with natural laws and attain higher moral and spiritual truths.
Step-by-step explanation:
Thomas Aquinas recognized two key types of reason with which human beings discern and abide by different laws of existence. Aquinas's work is deeply grounded in his belief in ethical naturalism and the view that humans are capable of understanding and conforming to the laws of nature through reason. Additionally, while empirical data or sense observation is critical in understanding the physical world, Aquinas also acknowledges the importance of divine revelation for certain truths that human reason cannot grasp alone.
Human beings have the capacity for practical reason, which is used to discern natural laws and create human laws. However, Aquinas asserts that there is also a type of higher reason that comes from divine revelation, offering knowledge that cannot be reached through human reason alone. The interplay of these types of reason is central to Aquinas's conception of law and morality.
For Aquinas, human laws must be in alignment with natural law, as laws that violate natural principles are considered invalid. Through the process of reasoning, humans can understand the natural world and establish societal norms that reflect these underlying principles. This conception forms an integral part of Aquinas's contribution to classical natural law theory.