No art manifestation is really isolated. However new it may seem, it is always based upon the previous epochs. The true masters do not give lessons, because art cannot be taught, but they set the example. To admire them does not mean to imitate them: it means the recognition in them of the principles of originality and the comprehension of their source, so that this eternal source may be called to life in oneself, this source which springs from a sincere and sympathetic vision of the aspects of life. The Impressionists have not escaped this beautiful law. I shall speak of them impartially, without excessive enthusiasm; and it will be my special endeavour to demonstrate in each of them the cult of a predecessor, for there have been few artistic movements where the love for, and one might say the hereditary link with, the preceding masters has been more tenacious. The Academy has struggled violently against Impressionism, accusing it of madness, of systematic negation of the "laws of beauty," which it pretended to defend and of which it claimed to be the official priest. The Academy has shown itself hostile to a degree in this quarrel. It has excluded the Impressionists from the Salons, from awards, from official purchases. Only quite recently the acceptance of the Caillebotte bequest to the Luxembourg Gallery gave rise to a storm of indignation among the official painters. I shall, in the course of this book, enter upon the value of these attacks. Meanwhile I can only say how regrettable this obstinacy appears to me and will appear to every free spirit. It is unworthy even of an ardent conviction to condemn a whole group of artists _en bloc_ as fools, enemies of beauty, or as tricksters anxious to degrade the art of their nation, when these artists worked during forty years towards the same goal, without getting any reward for their effort, but poverty and derision. It is now about ten years since Impressionism has taken root, since its followers can sell their canvases, and since they are admired and praised by a solid and ever-growing section of the public. The hour has therefore arrived, calmly to consider a movement which has imposed itself upon the history of French art from 1860 to 1900 with extreme energy, to leave dithyrambics as well as polemics, and to speak of it with a view to exactness. The Academy, in continuing the propagation of an ideal of beauty fixed by canons derived from Greek, Latin and Renaissance art, and neglecting the Gothic, the Primitives and the Realists, looks upon itself as the guardian of the national tradition, because it exercises an hierarchic authority over the _Ecole de Rome_, the _Salons_, and the _Ecole des Beaux Arts_. All the same, its ideals are of very mixed origin and very little French. Its principles are the same by which the academic art of nearly all the official schools of Europe is governed. This mythological and allegorical art, guided by dogmas and formulas