I gave a version of this talk as a plenary lecture at the 15th Conference of the Polish Cognitive Science Society on Sept 23, and it was quite well received, even if there was much to discuss. There are some novel ideas expressed, also for me, and I look forward to more feedback, before I turn it into a paper! Welcome to the (old) room or on zoom, from 15:00 with cameras on.

For a quarter of a century, I have been engaged with various hierarchical models of semiosis, where lower levels are more fundamental than higher ones, in the sense that higher levels presuppose the lower ones, but not vice versa. The models have differed extensively in terms of the levels proposed, and on whether these can be defined empirically, as in early versions, or rather transcendentally – in terms of essential features of consciousness - in later versions (e.g. Zlatev 2018).

After a historical review, I wish to present the latest version of the Semiotic Hierarchy (Zlatev in press), and to show how it aims to be both transcendental and empirical: the latter by examining evidence for the presence of each level in the semiosis (and thus consciousness) of non-human animals. In short, the lowest level, and in a sense the ultimate “semiotic threshold” is that of sentience. Here there is “specious present” (James), but not yet any categoriality, which implies perceptual judgements: not just “I see X”, but “I see that X is Y”: though still constrained to the present, and long before any sign use or language. The third level goes beyond the present into remembering, planning and imagination. Yet, even here there is no sign use – while signs like pictures, gestures and words require a conscious differentiation between expressions and their intentional objects, as argued by Sonesson (2026). Languages, with their complex grammars designed for the expression of propositions and narratives, make up the fifth and final level.

For each of the levels, I will present evidence for how they seem to appear in animal consciousness. Concerning the fourth level, the only clear evidence for non-human sign use is where some individuals of all great ape species (chimpanzee, bonobo, gorilla, orangutan) have undergone extensive human enculturation and training in the use of signs (e.g., Miles 1999). Yet, even these highly special individuals fail to develop the fifth level: language. The explanation for this fact, however, lies not in their lacking any Chomskyan innate mechanisms, but in the observation that ever since the second level, categoriality, their skills corresponding to human semiosis, are only partial.

Miles, H.L. (1999). Symbolic communication with and by great apes. In The Mentalities of Gorillas and Orangutans, S. Taylor Parker, R.W. Mitchell and H.L. Miles (eds), 197-211 Cambridge: Cambridge University Press.

Sonesson, G. (2026). Semiotic investigations: From meaning to pictures and communication. De Gruyter Brill.

Zlatev, J. (2003). Meaning = Life (+ Culture). An outline of a unified biocultural theory of meaning. Evolution of Communication 4 (2), 253-296.

Zlatev, J. (2018). Meaning making from life to language: The Semiotic Hierarchy and phenomenology. Cognitive Semiotics, 11(1). 20180001.

Zlatev, J. (in press). Five pillars of cognitive semiotics. In A. Bilgari (Ed.), Open Semiotics (Vol. 5). Editions L’Harmattan.