This principle, popularized by James Hutton and Charles Lyell, states that the geological processes we observe today have been operating at the same rate and intensity throughout Earth's history. This means that we can understand past events by studying the present.

Key points of uniformitarianism:

* Gradualism: Changes happen slowly and steadily over long periods.

* Present is key to the past: Studying current processes helps us interpret past geological formations.

It's important to note that while uniformitarianism is a valuable principle, there are exceptions. Some geological events, like asteroid impacts, are catastrophic and do not occur regularly. Additionally, the rate of some processes can vary significantly over time.