天主教自從1891年教宗良十三世以通諭的方式具體回應當時歐洲工業革命後的社會問題，也就是勞動問題，開啟了教會建構社會理論、勞動理論的里程碑。本文主要論述歐美主流的勞動理論思想的兩大體制：個人主義的自由經濟主義及集權主義的社會主義影響之下爭議不斷，勞動應顯出人的價值，天主教會百年來論述勞動問題的五個通諭除了承繼信仰傳統對勞動的概念，還對應兩大體制的觀點發展出獨特的內涵。天主教勞動理論奠基於基督人學、對人的尊嚴的概念，五個通諭有一體性及發展性，尤以教宗若望保祿二世《論人的工作》通諭有突破性的勞動觀，區分勞動的主觀意義與客觀意義，從而延伸出勞動主觀意義優於客觀意義、勞動優先於資本、在財產的所有權及使用權上區分發展出政府的責任，以達到公共利益及尊重人的基本需要。天主教的勞動理論一方面肯定兩大體制的勞動概念，但是具有更寬廣及超越視野的勞動理念。

Ever since 1891 when Pope Leo XIII wrote an encyclical in response to the social problems, notably the problem of labor, brought about after the industrial revolution in Europe, the Catholic Church began to shape its social doctrine and teaching on labor. This paper presents the two main currents of thought about labor in Europe and America: the individualism of liberal economics and the communitarianism of socialism, and their continual strife. Work, however, ought to be a sphere in which the value of the human being can be highlighted. Over the past hundred years Catholic teaching on this subject has been outlined in five encyclicals, which, on the one hand, apply the tradition of the faith to the issue of work, and, on the other, develop a unique theory that is distinct from both the above. The Catholic theory of labor is based on Christian anthropology and respect for the human person. The five encyclicals share a common discourse and yet also show development. Pope John Paul II’s Laborem exercens is particularly striking for its new understanding of work, which distinguishes between a subjective and an objective sense, and prioritizes the former over the latter and prioritizes labor over capital. In distinguishing between the right to property and the right to its use, the encyclical stresses the responsibility of the government to meet the basic needs of the common good and respect for the human person. The Catholic theory of labor confirms the ideas of work held by the two main schools of thought but contributes a broader and more far-reaching vision of labor.