Intellectual work requires "surfaces" to work against, almost as an exact analogy to substrates in chemistry which help to catalyze reactions. The surfaces may include: - articles, books, or other writing against which one can think and write - colleagues, friends, family, other thinkers, or even imaginary characters (as suggested by C. Wright Mills) - one's past self as instantiated by their (imperfect) memory or by their notes about excerpted ideas or their own thoughts

Are there any other surfaces we're missing?

Mondelli, Mario U., Marta Colaneri, Elena M. Seminari, Fausto Baldanti, and Raffaele Bruno. ‘Low Risk of SARS-CoV-2 Transmission by Fomites in Real-Life Conditions’. The Lancet Infectious Diseases 0, no. 0 (29 September 2020). https://doi.org/10.1016/S1473-3099(20)30678-2.