Since Euclid, optics has been considered a geometrical science, which Aristotle defines as a “mixed” mathematical science. Hobbes follows this tradition and clearly places optics among physical sciences. However, modern scholars point to a confusion between geometry and physics and do not seem to agree about the way Hobbes mixes both sciences. In this paper, I return to this alleged confusion and intend to emphasize the peculiarity of Hobbes’s geometrical optics. This paper suggests that Hobbes’s conception of geometrical optics, as a mixed mathematical science, greatly differs from Descartes’s one, mainly because they do not share the same “mechanical conception of nature.” I will argue that Hobbes and Descartes also have in common the quest for a different kind of geometry for their optics, different from that of the Ancients. I will show that this departure is not recent since Hobbes’s approach is already evident in 1636, when he judges the demonstrations of his contemporary friends, Claude Mydorge and Walter Warner. Finally the paper broadly suggests what is noteworthy in Hobbes’s optics, that is, the importance of the idea of force in his mechanics, although he was not able to conceptualize it in other terms than “quickness.”

中文翻译：

---

霍布斯的几何光学

自欧几里得以来，光学一直被认为是一门几何科学，亚里士多德将其定义为“混合”数学科学。霍布斯遵循这一传统，并明确将光学置于物理科学之中。然而，现代学者指出几何和物理学之间存在混淆，并且似乎不同意霍布斯将这两种科学混合的方式。在本文中，我将回到这种所谓的混淆，并打算强调霍布斯几何光学的特殊性。本文认为，霍布斯的几何光学概念作为一门混合数学科学，与笛卡尔的有很大不同，主要是因为它们不共享相同的“自然力学概念”。我会争辩说，霍布斯和笛卡尔还有一个共同点，即为他们的光学寻求一种不同的几何学，不同于古代人的几何学。我将表明这种偏离并不是最近的事情，因为霍布斯的方法在 1636 年就已经很明显了，当时他评判了他同时代的朋友克劳德·迈多格 (Claude Mydorge) 和沃尔特·华纳 (Walter Warner) 的示范。最后，这篇论文广泛地提出了霍布斯光学中值得注意的东西，即力的概念在他的力学中的重要性，尽管他无法用“速度”以外的其他术语来概念化它。