By examining three objects – the zāʾirja, Ramon Llull’s ars combinatoria, and Leon Battista Alberti’s cipher disk – and the contexts of their development and transmission, this essay opens up a site of reflection on the ‘mechanisation’ of thought and reality through systems of rotating symbols. In this way, this essay not only extends discussions of semiotics and cryptography across pre-modern and early modern geographies, but also offers wider observations on how the material mediates the immaterial.