Aesthetic: Art is Harmony. Harmony is the analogy of opposites, the analogy of similarities of tone, of tint, of line taking account of a dominant an… - Georges Seurat

I insist on establishing the following dates indicating my prior paternity, [and the discussions that I held]
1884, 'Grande Jatte' study, exhibition of the Independants
1884-1885, 'Grande Jatte' composition
1885, studies at the 'Grande Jatte' and at Grandcamp; I took up again the 'Grande Jatte' composition October 1886. 4 October 85 I make Pissarro's acquaintance at Durand-Ruel's.
1886, January or February, a small canvas by Pissarro, divided and pure color, at Clozet's, the dealer on the Rue de Chateaudun.

Gaiety of tone is the luminous dominant, of tint, the warm dominant, of line, lines above the horizontal
Calmness of tone is the equality of dark and light; of tint, of warm and cool, and the horizontal for line.
Sadness of tone is the dark dominant; of tint, the cool dominant, and of line, downward directions.

The means of expression is the optical mixture of tones, of tints (of local color and the illuminating color: sun, oil lamp, gas, etc.), that is, of the lights and of their reactions (shadows) following the laws of contrast, of gradation, of irradiation.