A tension between solidity and fluidity tends to divide the sciences and the humanities along lines that define what is hard and soft in knowledge. This divide relates to similar dichotomies, between exteriority and interiority, material and spiritual, homogeneity and heterogeneity, matter and form, all of which have been partially mapped in Western thinking onto a traditional separation between earth and sky. Yet particular forms of knowledge sit uneasily within these tensions, a paradigmatic example of which is an understanding of solids as ‘viscous fluids’. This article explores the concept of viscosity, attending to how it has impacted on understandings of matter, as well as broader social and cultural issues. It does so, particularly, by looking into the scientific study of ice, a material that has historically been regarded as solidfluid, to argue that life and sociality remain possible only in so far as matter that is viscid allows solid and fluid states to mingle.

坚固性和流动性之间的张力倾向于按照定义知识的硬性和软性的界限来划分科学和人文学科。这种划分与相似的二分法有关，外在与内在、物质与精神、同质与异质、物质与形式，所有这些都在西方思想中被部分映射到传统的地球与天空的分离上。然而，特定形式的知识在这些紧张局势中令人不安，其中一个典型的例子是将固体理解为“粘性流体”。本文探讨了粘度的概念，关注它如何影响对物质的理解以及更广泛的社会和文化问题。它这样做，特别是通过研究冰的科学研究，冰是一种历史上被认为是固体流体的材料，