Can a clever financier outrun a diligent regulatory system? Are these recurrent excesses controllable, or are they an inevitable feature of economic life? The paper examines a representative history of financial illusions, specifically John Law's 18th century Mississippi Bubble, the original 1920s Ponzi scheme, the Investors Overseas Services (IOS) affair of the 1970s, and the Bank of Credit and Commerce International (BCCI) affair, illustrating the growth over time in the size and complexity of such institutions as well as some of their animating characteristics. If a certain level of entrepreneurial experimentation (deviltry) is a necessary and permanent fixture of the economy, and if we cannot successfully determine between the desirable and the undesirable before outcomes are known, we are faced with continuing growth along the continuum of financial illusion.