Bry from Philosophics Blog explores the enduring debate surrounding the definition of probability. The author highlights that despite centuries of discussion across various fields, no single interpretation has gained universal acceptance. The post outlines six prominent interpretations: classical, frequentist, Bayesian, propensity, logical, and quantum probability, briefly explaining the core idea and key challenges of each. It argues that the lack of consensus persists because probability is a multifaceted concept with different interpretations proving useful in different contexts. Ultimately, the author suggests that the philosophical contest over probability's meaning is likely to continue indefinitely. The blog post concludes by noting the practical success of probability across disciplines despite the fundamental disagreement about its definition.https://philosophics.blog/2025/04/02/whats-probability/