# Progress > **Progress** is defined as moving from [Problems](Problem.md) to better [Problems](Problem.md). All progress, both historic and today, comes from the quest for good [Explanations](Explanations.md) (hard to vary, while still accounting for what they purport to account for). This principle explains what the criterion for success is in science, where it leads to the principle of testability of theories, where the test constrains the explanation so that it is hard to vary. But it also applies outside physics, in philosophy, moral philosophy, aesthetics, and so on. The same principle applies and draws a distinction between ideas that have a chance of making progress, and ideas that have no chance of making progress. [Why Should we seek good explanations?](Explanations.md#Why%20Should%20we%20seek%20good%20explanations?) Because that is the best way to [solve our problems](Problem%20Solving%20Process.md), and therefore the best way to make progress. --- Date: 20240812 Links to: Tags: References: * [David Deutsch - What is Truth? - YouTube](https://youtu.be/3eEffbjzNwE?t=556)