“Power conversion is the capacity to convert potential power, as measured by resources, to realized power, as measured by the changed behavior of others.”

Source: Understanding International Conflicts: An Introduction to Theory and History (6th ed., 2006), Chapter 3, Balance of Power and World War I, p. 60.

Problems of Estimating Military Power, August 1966
Problems of Estimating Military Power (August 1966)

Change the World Without Taking Power (2002)

Source: Ancient Shores (1996), Chapter 30 (p. 331)

Source: A Return to Love: Reflections on the Principles of "A Course in Miracles" (1992), Ch. 7 : Work, §3 : Personal Power, p. 190 (p. 165 in some editions). This famous passage from her book is often erroneously attributed to Nelson Mandela. About the mis-attribution Williamson said, "Several years ago, this paragraph from A Return to Love began popping up everywhere, attributed to Nelson Mandela's 1994 inaugural address. As honored as I would be had President Mandela quoted my words, indeed he did not. I have no idea where that story came from, but I am gratified that the paragraph has come to mean so much to so many people."
Variant which appears in the film Coach Carter (2005): "Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness that most frightens us. Your playing small does not serve the world. There is nothing enlightened about shrinking so that other people won't feel insecure around you. We are all meant to shine as children do. It's not just in some of us; it is in everyone. And as we let our own lights shine, we unconsciously give other people permission to do the same. As we are liberated from our own fear, our presence automatically liberates others."
Variant which appears in the film Akeelah and the Bee (2006), displayed in a picture frame on the wall, attributing it to Mandela: "Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. We ask ourselves, Who am I to be brilliant, gorgeous, talented, fabulous? Actually, who are you not to be? We were born to make manifest the glory of God that is within us. And as we let our own light shine, we unconsciously give other people permission to do the same."
Context: Our deepest fear is not that we are inadequate. Our deepest fear is that we are powerful beyond measure. It is our light, not our darkness that most frightens us. We ask ourselves, Who am I to be brilliant, gorgeous, talented, and fabulous? Actually, who are you not to be? You are a child of God. Your playing small does not serve the world. There is nothing enlightened about shrinking so that other people will not feel insecure around you. We are all meant to shine, as children do. We were born to make manifest the glory of God that is within us. It is not just in some of us; it is in everyone and as we let our own light shine, we unconsciously give others permission to do the same. As we are liberated from our own fear, our presence automatically liberates others.

Source: Between Man and Man (1965), p. 152

Source: "The theory of economic regulation," 1971, p. 3; Lead paragraph
Context: The state --the machinery and power of the state-- is a potential resource or threat to every industry in the society. With its power to prohibit or compel, to take or give money, the state can and does selectively help or hurt a vast number of industries. That political juggernaut, the petroleum industry, is an immense consumer of political benefits, and simultaneously the underwriters of marine insurance have their more modest repast. The central tasks of the theory of economic regulation are to explain who will receive the benefits or burdens of regulation, what form regulation will take, and the effects of regulation upon the allocation of resources.