A fundamentally important stage of any successful campaign is the critical and intellectually immersive process that I define as ‘cutting the diamond’. Thinking of the diamond cutters of Antwerp helps describe this process. Diamond-cutters can spend up to two years carefully studying a single rough diamond, before analysing where the stone should be cut. It takes this long for them to decide where the knife must fall to illuminate the natural shape of an octahedral raw diamond crystal. They then ‘cleave’ the stone in a way that reveals clean surfaces, and reflects brilliance. The diamond of advocacy comes out of a parallel process, perfected by deep, empirical analysis. It takes immersion in both the issue and strategy by a small, astute and trusted group of stakeholders, working with ruthless concentration and focus. They work together for as long as it takes. They engage in rigorous research. They unpick arguments and put them back together again. They cut away their own prejudices and positions. They pay acute attention to the campaign’s intended audiences; to their values and beliefs. They challenge and may even have to change their own cherished beliefs. They turn the issue over and over and look for every possible weakness or flaw. They end up with an analysis that is clear and robust; one that stands up to all kinds of scrutiny and that rings true with a wider audience. Once the core group has ‘cut the diamond’ they will have the foundation of a campaign: a solid case that can then be communicated widely. The hard work will provide the campaign with a coherent analysis and strategy; achievable goals and ‘the asks’. ‘Cutting the diamond’ correctly helps campaigners frame the arguments and communicate the case in ways that are authentic, so that arguments resonate with a broad range of audiences. This will help galvanise a broad-based movement. This impact on wider audiences will in turn influence decision-makers. Above all it will ensure that the campaign is solid and invulnerable because all angles will have been carefully examined. ‘Cutting the diamond’ need not take more than a week, if the issue is not weighty. For a major issue – like climate change – analysis and framing could take a great deal longer.