地平線是物理的界限，也是想像的界限。地平線視閾的概念所隱含一系列的弔詭（線與面，遠與深，一條隨著人動而移動的線，等等）決定了地平線的複雜性與單純性。本文作者在論文中分別從地平線與風景畫之間的誕生與斷裂等層次，論述在西方藝術中地平線視閾與透視法的複雜關係。風景是難以用幾何來領悟的，只要其構成因素按嚴格分類（空氣、水、風、光等）而滑動。但是有一種讓風景與透視法共生的方式，告訴我們人性在風景中伸展的部分。這便是本文何以從瓦倫西安的畫開始的緣故。在藝術的領域裡，文藝復興的風景畫是與地平線同時誕生的。在此，阿爾伯蒂與布內勒奇都發揮了作用。在接下來的數世紀裡，地平線通常靜悄悄地躺在圖畫的背景裡，但也在風景畫裡顯現其自身，那是廢墟主題表現的極致。在十九世紀的繪畫中，地平線成為真正的主角，那時畫家以感覺為重而犧牲了透視法。深度的表現不再與地平線的視閾緊密相連。在時下的藝術中，地平線視閾依然相當重要：在注目凝視世界的真實存在時，還是需要想像力。而地平線視閾依然是分享世界的欲望的措辭。

As a physical boundary, the horizon is also an imaginary one. The notion of horizon sums up a series of paradoxes (line and zone, far and deep, a line that moves when we move, etc.) that define its complexity and singularity. Among those, I will propose a reflection on its links with perspective in art. Landscape is hard to apprehend with geometry, as long as its component are sliding through any kid of strict classification (air, water, wind, light, etc.). But there is a way to make it live with perspective, which tells us the part of humanity that lies in the landscape. This is the reason why I start by the image of Pierre Henri de Valenciennes. The birth of renaissance landscape is simultaneous with the birth of the horizon in the artistic field. Alberti and Brunelleschi play here the major role. In the following centuries, the horizon usually lies quietly in the background of the picture, but also appears for itself in landscape paintings, when the motif of the ruins is extremely represented. It will become a real actor in the 19th century painting, when the painters chose to sacrifice perspective against the sensation. Representation of the depth is no longer tight to the horizon. In art today, the horizon is still very important: it still claims our need of imagination, while looking at the reality of the world. The desire of sharing the world is still the word of the horizon.