Beautiful lecture. As with a lot of things that shape our everyday life we forget to contemplate their qualities. For example fonts subtly impact how we perceive, understand, feel about any text yet we fail to give it much thought as Etienne points out. A shape of a letter, especially in math papers, can influence how "beautiful" and understandable the proof is. Really appreciate that Knuth spent years building LaTeX so that compsci and math papers could be formatted as beautiful PDFs and not published as Word documents