C. S. Peirce used the syntagm “ken of sense” (or “the ken of the senses”) while he was writing an elaborate critique of a book describing a series of cases of telepathic hallucinations (the collection Phantasms of the Living, edited by E. Gurney, F.W.H. Myers, and F. Podmore in 1886).
In order to reveal the meaning of this syntagm used by Peirce (also written in the form “senses’ ken”), I first present a history of the very rich meaning of the word “ken” in English but also of the use of other words with a similar meaning, by other authors such as Lucretius (of whom Peirce confesses at one point – in MS 1604 – that he read only parts of, although it would have been worthwhile to dedicate a real study to it).
I will show how, to explain the meaning of this syntagm, Peirce, for analytical reasons, first came to the distinction between the psychological term “percept” (res percepta) and perceptual judgment, and then to the proposal to consider, under the name of “percipuum”, the percept as it is immediately interpreted in perceptual judgment. I will then present Peirce’s view on the percipuum, starting from his conception that the percept is not the only thing that we ordinarily say we “perceive”, and from the fact that we cannot refuse the name of perception to much which we rightly reject as unreal (such as dreams and hallucinations that are quite often classified as perceptions). As for the subject of perceptual judgment, Peirce presents it as a sign, and although his explanation is often obscure (it is part of an unfinished project from 1903, recorded in CP 7.597–688) it is quite clear that perceptual judgment is not a copy, an icon, or a diagram of perception. Perceptual judgment can thus be considered as a higher degree of the operation of perception.
Finally, I comment on Peirce’s conclusion that percipuum is a recognition of the character of what is past, the percept which we think we remember, in which case telepathy, as he says, would be a somewhat more remote phenomenon from perception than the conjectures by which physicists so often hit upon truth.
PhD from the University of Bucharest. He is scientific researcher at the Constantin Rădulescu-Motru Institute of Philosophy and Psychology of the Romanian Academy. He is author of the book Orizonturi logice în filosofia românească din secolul al XX-lea (Logical Horizons in the Romanian Philosophy of the Twentieth Century) and of many articles, published in Romanian, about C. S. Peirce. He is co-author of the volume Kants Schriften in Übersetzungen (Felix Meiner Verlag, 2020). He has participated in recent years at the IASS-AIS World Congresses of Semiotics (Kaunas, 2017; Buenos Aires, 2019) and at the 11th Conference of the Nordic Association for Semiotic Studies (Stavanger, 2019).