Charles S. Peirce

A Quincuncial Projection of the Sphere

FOR meteorological, magnetological and other purposes, it is convenient to have a projection of the sphere which shall show the connection of all parts of the surface. This is done by the one shown in the plate. It is an orthomorphic or conform projection formed by transforming the stereographic projection, with a pole at infinity, by means of an elliptic function. For that purpose, 1 being the latitude, and 0 the longitude, we put Cos2 1 COS2ICOS2OSill I 1 + V1-cos2I cos2d and then +FPp is the value of one of the rectangular co6rdinates of the

Division of signs

Transcribed by Ahti-Veikko Pietarinen. Hereby we publish five (previously unpublished) excerpts from Charles S. Peirce’s manuscripts – one from the Prescott Book (MS 277, 1909) and four from the Logic Notebook (MS 339, October 1905–March 1906, 1909). These concern the problems of classification of signs.

On the Ghosts in Rutherfurd's Diffraction-Spectra

This is supposing the opaque lines to have a constant breadth, (1 X) w. Suppose the collimator an (d telescope of the spectrometer to be focused for parallel rays, and neglect the angular aperture of the slit. Let the angle of incidence be i, and the angle of einergence j. Write = sin i sin j. Then the ray which strikes the gitter at a distance x from the line of reference is longer than that which passes through the line of reference by vx. Consequently, the resultant oscillation from the rth slit will be

Two Letters to Lady Welby

The two letters in this chapter are written by the US philosopher Charles Sanders Peirce. They form an essential part of Lady Welby’s own intellectual and philosophical development, and are of greatest importance for those who study semiotics and in Peircean philosophy in general, with its emphasis on meaning, significance and the categories of Firstness, Secondness and Thirdness. The letters are a great dialogue, and add powerful autobiographical lines to their profile.

Firstness, Shock, Law, and the Hand of the Sheriff

The three: shock, law, and the hand of the sheriff, are an image of a philosophical consideration on legal activity. Shock is inherent to the experience of Firstness. Encountering the law always includes such a shock (a never fully extended suggestion in the center of Peircean philosophy). The hand of the sheriff is a sign, a metaphor, a reality and a symbol: their determination depends on the situation in which the occurrence takes place.

Chapitre 3. Comment rendre nos idées claires

Pour peu que l’on ait ouvert un traite moderne sur la logique telle qu’on l’enseigne d’ordinaire, on se rappellera sans doute qu’on y divise les conceptions en claires et en obscures, en distinctes et en confuses. Ces divisions se rencontrent dans les livres depuis pres de deux siecles, sans progres et sans changement, et les logiciens les mettent generalement au nombre des perles de la science. On definit idee claire une idee saisie de telle sorte qu’elle sera reconnue partout ou on la renco...