Geoscience is the study of Earth history and processes, a study so broad that individual geoscientists may have little knowledge or skill in common. This essay asserts that there is, nonetheless, a common set of perspectives, approaches, and values that characterizes the discipline. Geoscientists are united by a common commitment to testing hypotheses against observations of the natural system using multiple converging lines of evidence. Geoscientists test hypotheses by comparing modern processes to those found in the rock record; comparing related examples to understand commonalities and differences attributable to process, history, and context; finding multiple converging lines of evidence; and comparing observations to theory-based prediction. They share the perspective that observation and a spatial and temporal organizational scheme are fundamental to understanding Earth systems and processes. Their interpretations are grounded in a common understanding that Earth represents a long-lived, dynamic, complex system for which a 4.6-billion-year history has been shaped by processes operating at different rates. These methods and approaches have evolved over time because they are particularly well adapted to studying Earth. A geoscientist brings this approach to any collaboration, as well as deep knowledge and skill for studying a particular aspect of Earth, and a set of cultural values that support collaborative problem solving. Developing such individuals is the central goal of geoscience majors and graduate programs.