From Hans L. C. Jaffe, "Picasso":
"However, at the end of , when Picasso returned to Barcelona, a deep and significant change took place in his painting. This change strikes us first of all in his choice of colors: the variable range of brilliant tones yields to a single dark and oppressive blue. But this transformation in his painting - the first in a long series - was more than a mere change in color, more than the adoption of a new tonality. It was above all the result of a new attitude toward people. Instead of observing them ruthlessly and satirically, he now treated his models with sympathy, with melancholic tenderness. His subjects changed, too. Instead of painting café scenes, Parisian interiors with women in big hats seated at tables and drinking, he began to represent, to imagine enigmatic, emaciated figures standing rigid and silent against a vague or empty background. These men and women no longer evoke contemporary life, they have nothing in common with the tense, nervous atmosphere of Paris at the beginning of this century; they are beggars, blind men, and poor street artists, transformed by the painter's compassionate and affectionate vision into almost mythical figures that belong to no particular, or familiar, epoch. The atmosphere in which Picasso places them is more or less that in which similar figures appear in Rilke's poems, written the same year, 1901 - an atmosphere of solitude, hunger, and everyday misery, borne with dogged courage. And this spiritual atmosphere is suggested not only by the angular lines of the emaciated bodies, but above all by the sad, distressing color, the subdued blue, which dominates the pictorial space and the figures by its remote and silent unreality.
"Child with a Dove, probably painted near the end of 1901, is the first of the series of canvases that comprise Picasso's Blue Period. Here, the artist's tenderness manifests itself for the first time, in clear contrast with the spirit of sharp and satirical observation that characterized the street and café scenes. Was it the theme of childhood that led Picasso to discover this poetry of tenderness? Or was it the detail of the dove that awakened memories of his childhood, when he often watched his father painting pigeons? However that may be, Picasso was conscious of his change in style: from 1901 he signed simply "Picasso," where previously he had used also his patronymic of Ruiz (or its abbreviation).
"His second trip to Paris, in 1901, also brought a change in his personal landscape, as his circle of young Catalan bohemian friends was replaced with a group of Parisian poets and eccentrics, among them Max Jacob, whom he had met at Vollard's, and Gustave Coquiot, the art critic of whom he painted two portraits during this visit. The work of his Blue Period - during which he produced a number of paintings showing solitary figures such as the portrait of his friend Sabartés, or the guitarist, or the old Jew - was done partly in Paris and partly in Barcelona. In 1902 Berthe Weill and Vollard again exhibited his paintings. He was then in Barcelona, and did not return to Paris until the end of the year. He stayed a few months; early in 1903 he was back in Barcelona, to remain until early in 1904.
"The fact that most of the works of the Blue Period were painted in Barcelona accounts for the resemblance of many of his models to figures by El Greco. His affinity with this master of Spanish Mannerism is apparent in the great composition of 1901, which dates from the beginning of the Blue Period - the evocation or burial of the painter Casagemas, now in the Petit Palais in Paris. Like El Greco's Burial of Count Orgaz, this painting is divided into two zones, one earthly and the other transcendent; the element of pathos that appears here for the first time arises from Picasso's deeply felt attachment to his friend. In the paintings of the immediately following years this affinity with El Greco asserts itself more and more. The elongated proportions, the ecstatic and angular gestures, the relation between space and figures, all this brings to mind the great Spanish master, but the feeling in Picasso's works remains authentically his own. He makes use of El Greco's elongated forms and hallucinatory space, but he employs these elements to express a feeling peculiar to his time-solidarity with distressed, famished, oppressed humanity. Celestina is a superb example of this feeling and of the style in which it found its form: this portrait of an old one-eyed woman, dressed in somber color, achieves, thanks to the simplicity of its color and the economy of its line, an austere nobility which relates it to El Greco's most restrained portraits. From the same year, 1903, dates the enigmatic, symbolic composition entitled La Vie, showing a nude couple and a woman with a child in her arms; this painting, with its long, slender figures, has the same feeling of melancholy tenderness. But Celestina, above all, and the canvas representing a blind guitarist (The Art Institute of Chicago), show Picasso's affinity with El Greco and the way he makes use of it to express his solidarity with, his active compassion for, the poor, to whom he belonged himself in that period of his life. At the beginning of the century he, like Rilke, was one of the young artists who felt distressed at the sight of human misery, and expressed this feeling in sober, ascetic, austere works, with a restraint that precluded sentimentality or bathos."