Descartes' first principle was "Cogito, ergo sum" ("I think, therefore I am"), emphasizing the certainty of self-existence through the act of doubting. His second principle was the distinction between mind (res cogitans) and body (res extensa), setting the foundation for his dualistic metaphysical framework.

Hermann Schr odter has written:

'Metaphysik des Ichs als res cogitans: Ideen und Gott: zu Stellung, Struktur und Funktion des Geottesbeweises bei Descartes' -- subject(s): Philosophie, SEL Library selection

The Latin meaning of 'thinking person' is homo cogitans. In the word-by-word translation, the noun 'homo' means 'man'. The word 'cogitans', as the adjective form of the present participle of the verb 'cogito', means 'thinking'.

Semper cogitans.

Francesco Pellizzi has written:

'Res: Anthropology and Aesthetics, 16, Autumn 1988 (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 12, Autumn 1986 (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 34, Autumn 1998: Architecture (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 9, Spring 1985 (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 48, Autumn 2005: Permanent/Impermanent (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 44, Autumn 2003: Anthropology and Aesthetics (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 38, Autumn 2000 (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 39, Spring 2001: African Works (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 15, Spring 1988 (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 11, Spring 1986 (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 47, Spring 2005 (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 31, Spring 1997: The Abject (Res: Anthropology and Aesthetics)'

'Res: Anthropology and Aesthetics, 35, Spring 1999: Intercultural China (Res: Anthropology and Aesthetics)'

'RES'