We explore the evolving relationship between science and government through the lens of institutional development, the social contract for science, and science-for-policy mechanisms. Beginning with the founding of early scientific societies, liberal democratic ideals enabled intellectual autonomy in exchange for societal benefits such as public health and technological innovation. The Linear Model of Innovation became the foundational myth sustaining public investment in basic science and explains its role in shaping post-WWII “Big Science” initiatives, such as the Manhattan Project and the Human Genome Project. Through historical case studies—from vaccine development to the Fukushima nuclear disaster and the Thalidomide crisis—we critically examine how science informs policy, succumbs to the risks of regulatory capture and the tensions between objectivity and political influence. Concepts such as the Iron Triangle, boundary work, and philanthrocapitalism are used to show how scientists, policymakers, and stakeholders co-produce knowledge and shape evidence-based policy. The chapter concludes by highlighting emerging challenges in maintaining scientific integrity amid growing commercialisation, stakeholder activism, and populist pressures in democratic systems.