In 'The Knowledge Machine,' Michael Strevens presents a groundbreaking argument that challenges our conventional understanding of scientific progress. He asserts that modern science, far from being a purely rational enterprise, owes its success to an 'iron rule of explanation' – a disciplined yet arguably irrational adherence to empirical evidence that intentionally excluded metaphysical and philosophical arguments. This controversial thesis posits that this peculiar constraint, paradoxically, was the engine behind science's unparalleled objectivity and predictive power. Strevens meticulously traces this rule's impact from the scientific revolution to today, offering a profound reinterpretation of how humanity came to unlock the secrets of the universe.