A natural system of fundamental physical units $c$, $\hbar$, and $m_p$ is discussed, where $c$ is the velocity of light, $\hbar$ is Planck's constant, and $m_p$ is the Planck mass, which is related to the Newtonian gravitational constant by the equation $m_p^2=\hbar c/G$. In a natural system of units, such questions as: ``How does the anthropic nature of the physical universe arise? Is it unique, or does an infinite set of universes exist?'' and ``Are the fundamentals of the physical universe knowable and what is the strategy for knowing them?'' become particularly urgent.