Abstract Thomas A. Sebeok’s name became all but synonymous with semiotics during the last half of the twentieth century. Sebeok located neglected semioticians in antiquity, and convinced many contemporary scholars that they were semioticians. One of his most fruitful encounters was with Juri Lotman of the Tartu–Moscow School of Semiotics, who had published in 1967 an ambitious model of human sign systems in which language would constitute a primary modeling system, and cultural phenomena a secondary modeling system. We inspect how Sebeok amended Lotman’s system, inserting another primary modeling system before language. This brings biological precursors to human language as a syntactic and learned faculty that builds on many nonsyntactic and sometimes nonconscious senses, including emotion, affect, and memory. We note how, in Sebeok’s final book in 2000 on modeling systems theory, co-authored with Marcel Danesi, there is a suggestion that the three layers of modeling systems may be colored by Peircean notions of firstness, secondness, and thirdness; we clarify how these layers are analogue. Finally, the fundamentals of the primary modeling system leak into languaging, as better understood through post-Sebeok cognitive and neurological sciences, and rendering less mysterious some of the strange effects of the COVID-19 pandemic’s proxemics crisis.