Here's why:

* Uniformitarianism states that the geological processes that operate today have operated in the same way throughout Earth's history.

* This means that the physical, chemical, and biological laws that govern these processes are consistent over time.

* By understanding these laws and observing their effects today, we can infer how similar events shaped the Earth in the past.

Example: We see erosion happening today, causing changes to the landscape. Uniformitarianism suggests that erosion has always worked in a similar way, meaning we can use modern erosional patterns to understand how landforms evolved in the past.