In this chapter, I explore the necessary conditions for using contingent propositions for describing nature. For this purpose, I construct the conceptual apparatus that allows attributing conflicting truth-values to the same proposition without a contradiction. This conceptual apparatus is found to be identical to the temporal indexical expressions of past, present, and future. Hence, time, and more specifically the “flow of time,” is found to be a necessary and the most fundamental feature of nature. I further explore this conceptual structure and show that it relies on a notion of objectivity, which distinguishes between propositions and what they describe.