“A subject interests me and holds my attention only so long as it presents me with difficulties, only so long as I am at odds with it and have, as it were, to struggle with it; but once I have mastered it I hurry on to something else, to a new subject; for my interest is not confined to any particular field or subject; it extends to everything human. This does not mean that I am an intellectual miser or egoist, who amasses knowledge for himself alone; by no means! What I do and think for myself, I must also think and do for others. But I feel the need of instructing others in a subject only so long as, while instructing others, I am also instructing myself.”

Source: Letter to the Earl of Bute (November 1760), quoted in Letters from George III to Lord Bute, 1756–1766, ed. Romney Sedgwick (1939), p. 50

Quoted from: Antonio Rodríguez, "Una pintora extraordinaria," Así (17 March 1945)
1925 - 1945
Variant: I paint self-portraits because I am so often alone, because I am the person I know best.

Source: Death Masks

Source: The World We Want (2000), Chapter 2, Rights And Duties, p. 68

Estoy tan poco en mí, que lo que hacen de mí, casi no me interesa.
Voces (1943)

Letter X: Reply to the Edinburgh Reviewers, Miscellaneous works of the late Thomas Young https://archive.org/details/miscellaneouswo01youngoog (1855), p. 215

Source: Les Fleurs du Mal

Letter to Alfred Galpin (27 May 1918), published in Letters to Alfred Galpin edited by S. T. Joshi, p. 18
Non-Fiction, Letters