What is Science?

Science is often misunderstood as a static collection of facts or a quest for absolute, irrefutable truth. The authors argue that this is fundamentally incorrect. Instead, science is a method—a strategy for understanding the world that emphasizes the use of statements that can be examined to see if they are wrong. At its core, science is a critical endeavor. It is not about proving theories, but about subjecting them to the harshest possible tests. A statement is considered scientific only if it is falsifiable, meaning there must be some imaginable observation that could prove it wrong.

The scientific method is characterized by a structured, iterative process. It begins with a puzzle—an observation that contradicts our expectations. Researchers then construct a theory or model, which is a set of logically consistent statements explaining why the phenomenon occurs. A good model is a simplified picture of reality, designed not to capture every detail, but to explain the specific puzzle at hand. From this model, researchers derive testable implications (hypotheses). The final steps involve observing the world to test these implications and evaluating the results. If observations are consistent with the theory, it is provisionally corroborated; if they are inconsistent, the theory must be rejected or revised.

The authors emphasize the importance of formal logic in theory testing. They distinguish between valid and invalid arguments, noting that science relies on the logic of 'denying the consequent.' If a theory predicts an observation and that observation does not occur, the theory is logically falsified. Conversely, observing a predicted outcome does not 'prove' a theory, as other processes could have produced the same result. This asymmetry is the foundation of falsificationism: we can never be certain a theory is true, only that it has not yet been proven false. This makes scientific knowledge inherently tentative.

Finally, the authors dispel common myths about science. They clarify that science does not require experimental manipulation (as seen in fields like paleontology), nor does it require that a theory be tested immediately to be considered scientific. Crucially, they address the role of the scientist, noting that while the method is value-neutral, the individuals using it are not. Because researchers bring their own biases and social perspectives to their work, the scientific community must rely on diversity and open criticism to check individual biases and reach a consensus that is as objective as possible.