IX. Was Gauguin capable of attacking his colleague physically?
Many contemporates who knew Gauguin affirmed that he was always prepared to fight if he believed he was being attacked, that he lived according to his own rules, that he was ruthless, aggressive and irascible.
He was short-tempered and showed a presumptuous poise, a sly intelligence, and was always watching his back. Some thought that he possessed "butcherbird's killer instincts".* He had even punched his wife Mette in her face.23
Therefore, it is easily conceivable that he didn't hesitate to attack his colleague with his sword that night, either because he felt that he had to defend himself against an attack (perhaps with a razor?), or simply because Van Gogh had become too irritating or intrusive in his personal space.
* Douglas W. Druick/Peter Kort Zegers (eds.): Van Gogh and Gauguin – The Studio of the South; Chicago (Thames & Hudson) 2001, p. 264
23. see Letter of Gauguin's son Emil Gauguin to George Crès, 4 June 1926, quoted in Merlhès 1989, p. 19-20