Writing shortly before the birth of the cinema, Friedrich Engels described how the mechanisms of the stock exchange represented the world market as inverted reflections, ‘standing on their heads.’ Using this explicitly optical metaphor – which also describes the precise relationship between image and subject in a camera obscura – Engels claimed that stock exchange reports were ‘utterly useless for the course of industry’ because the ‘gentry’ who relied on them ‘tried to explain everything from crises on the money market, which were generally only symptoms.’ To Engels, the metaphor of an ‘inverted reflection’ represented the idea that though financial markets depend on underlying economies of goods and services, they are effectively only representations of these economies and often move independently from them. Further, this is a visual metaphor that relies on a conception of financial activity as a vast labour of representation that inverts cause and effect according to the logic of the ‘nervous system’ of the market itself. At the turn of the twentieth century, this optical metaphor was the subject of debate between those who embraced the idea of the market as a camera that provided accurate ‘snapshots’ of the economy – in Joseph Schumpeter's words – as opposed to those who, like Engels, claimed that this optical and cinematic arrangement produced only a self-fulfilling illusion.