Final answer:
Option (b), Thales believed that water is the most basic reality because of its ability to exist in different states and its crucial role in sustaining life. His monistic view suggested that behind the diversity of nature, there is a singular substance that constitutes the essence of everything.
Step-by-step explanation:
Understanding Thales's Belief in Water as the Fundamental Reality
Thales believed that water is the most basic reality due to its transformative nature in various states. Thales's perspective stems from his observation that water can exist in different forms - liquid, solid, and gas - demonstrating a form of Unity in Difference. This belief aligns with the idea that despite the various appearances of things in the universe, there is an underlying unity where everything is composed of the same 'stuff'.
Aristotle reflected on Thales's viewpoint by noting that all things seem to require water to live and grow, implying that water is central to existence and the processes of life. Moreover, Thales's observation that everything can be nourished and sustained by water helped him to postulate that water is the underlying principle of all that exists.
While Thales's methodology prioritized reason and perhaps underestimated empirical evidence, his monistic approach to understanding the universe laid the groundwork for subsequent philosophical inquiry, influencing future metaphysical concepts about the fundamental nature of reality.