Each of these Analysing Architecture Notebooks is devoted to a particular theme in understanding the rich and varied workings of architecture. They can be thought of as addenda to the foundation volume Analysing Architecture, which first appeared in 1997 and has subsequently been enlarged in three further editions. Examining these extra themes as a series of Notebooks, rather than as additional chapters in future editions, allows greater space for more detailed exploration of a wider variety of examples, whilst avoiding the risk of the original book becoming unwieldy. Curve is a divisive issue in architecture. Some see curves as expensive and decadent; others as an expression of transcendence – a way that the human mind can express its freedom from quotidian constraints. Yet others use curves to emulate some of the most beautiful forms in nature. This Notebook considers the various authorities to which architects look for the generation of their curves. It also considers the aspirations curves manifest in architectural form.