Western thought, since the Renaissance, shows a repeated development of methods aimed at attacking Christianity, from Machiavelli’s Classicist militarism up to William James’ ‘empty’ Pragmatism. Methods have aims, and aims are subject to norms and criteria. A summit of anti-Christian enmity – in middle Modernity - was the pre-Revolutionary French philosophes, headed by Voltaire. In the previous article I have shown how the Neo-Classicist Voltaire developed a hermeneutic in which the Classical Greeks and Romans always appear as tolerant and virtuous, and Christianity is presented as misleading, intolerant, oppressive, violent and criminal – all through its history. In this article I investigate the nature of ‘light’ in the name ‘Enlightenment’, in order to understand Voltaire’s alternative to Christianity. I argue that the philosophical term ‘light’ was rooted in Plato, developed and adapted by Augustine and Scholasticism, and became a basis for group mystical elitism in Joachim of Fiore. In Modernity – specifically Voltaire – the light becomes a replacement of the Medieval divine Logos (Law-word) – a new light for elitist groups. Modernity separated the Origin (causa efficiens) from the Destiny (causa finalis): the divine was split between ‘Nature’ (origin) and (super-natural) ‘Rationality’ (scientific and civil); linked these two with the faith in progress. The ‘light’ was insight into ‘natural law’ a priori in consciousness; an ambiguous ‘natural law’ expressing the bio-mechanical and the basis of civility, driving humankind to progress. Thus insight into the laws of physics – from Logos Newton via Caesar Voltaire – provides the basis for a rational society: scientific reason supports practical reason. Voltaire’s insistence on the natural right of women to be incubators of workers and soldiers (adopted by the French Revolutionaries) shows how difficult it was to derive the human from the natural.