Empiricism Without the Senses: How the Instrument Replaced the Eye

On receiving news of Galileo’s observations of the four satellites of Jupiter and the rugged face of the moon through his newly invented perspicillum, Kepler in great excitement exclaimed: Therefore let Galileo take his stand by Kepler’s side. Let the former observe the moon with his face turned skyward, while the latter studies the sun by looking down at a screen (lest the lens injure his eyes). Let each employ his own device, and from this partnership may there some day arise an absolutely perfect theory of the distances. This Hollywood-like scene of the two astronomers marching hand in hand toward the dawn of a new scientific era was no attempt by Kepler to appropriate Galileo’s success or to diminish the novelty of the telescope. On the contrary, Kepler repeatedly asserted how short sighted he was in misjudging the potential for astronomical observations inherent in lenses, and how radically Galileo’s instrument transformed the science of astronomy. It was a deep sense of recognition that beyond their different scientific temperaments and projects, they shared a common agenda of a new mode of empirical engagement with the phenomenal world: the instrument. For Kepler and Galileo, empirical investigation was no longer a direct engagement with nature, but an essentially mediated endeavor. The new instruments were not to assist the human senses, but to replace them

Magi from the North: Instruments of Fire and Light in the Early Seventeenth Century

The telescope emerged from a setting of natural magic, in the first place Della Porta’s writings on light and lenses. This paper aims a reconsidering the nature and meaning of the telescope as an optical instrument by taking this context seriously. It broadens the term ‘optics’ beyond the usual dioptrics, to a more general sense of controlling and manipulating light, sight and perception. In addition to historicizing the concept of optical instrument, it reflects upon the epistemic features of natural magic. Della Porta explained the properties of lenses in terms of the effects of artefacts on the images as they are perceived. This paper juxtaposes this ‘thinking with objects’ with practices of natural magic in the Low Countries. The central figure is Cornelis Drebbel, a resourceful inventor of optical instruments and in many ways comparable to Della Porta. In the course of this paper the reception of Della Porta in the Low Countries is also discussed. There was a prominent tradition natural magic in the North in which the work of Della Porta also found a modest place