As arguably the last period in European history when a transcendent understanding of space could be assumed, the Baroque was also a period in which the cosmos was conceived in mechanical terms. In this altered world-view, the traditional closed universe of the Middle Ages – and its subsequent humanist revisions in the Renaissance – were replaced by a more systematic and rational view of order. Expressed in the philosophies of René Descartes and Gottfried Wilhelm Leibniz, this world-view was supported by what was construed as the “self-evident” nature of mental reasoning: the circumspection of inner rational thought (as opposed to the perceived equivocations of outward dialogue redolent of humanism) provided the principal mechanism for distinguishing the mere appearance of things from their innate – and therefore essential – natures.