透過公共藝術凝結公眾所形成的公共領域，與一般的理論理性、認知理性有所不同，強調的是因為有眾人的參與所充實的實踐理性、實質理性，但是即便融入個體參與的歷程仍然讓人困惑不已，是否在形成共識後成為無異於理論理性的強制效力，也就是雷同黑格爾的精神歷程在最後達至絕對精神後取消其歷程。這個質疑本身是出於理論的推論，但是在實務工作上並不盡然如此，而給予理論建構無窮的暗示，本文就建成國中內兩件公共藝術作品觀察，侯淑姿的《快樂是什麼？》是就此主題訪問校內師生作成拼貼的影像，陶亞倫的《Take a break》則是會因師生踏入感應區域所形成的類似呼吸起伏的機械裝置，前者邀集師生共同的參與最後由作者予以選取集結，但是作者保留老師的成熟與學生的奇想特質，交由人物影像的姿態與神情發言，以拼貼的方式保有有各說各話的趣味，至於後者的機械裝置需要觀眾的參與才能啟動、才能解讀，預先保留與觀眾間互動的空間，顯示公共藝術有別於其他藝術形式在於強調觀眾投入邀集，並不預先設定內容與目標，甚至會因為觀眾的投入改變表現的內容。於是，為了呼應實務工作開啟的觀賞經驗，我們可以進行理論探討以求貼近，像是拉岡的的理論雖然是為精神分析的臨床診療奠定基礎，但是精神分析的臨床診療原本就在強調醫病間的互動，在分析師這個他人身上尋求他者而開啟個體可以走出自身的普遍性領域，拉岡以通往他者之路的不完全、不可能促使我們不斷進行與他人的互動，為我們揭示藝術最終是作為純粹的、空洞的藝術形式來達成普遍性的落實與充實。

The Publicity of Public Art is different from Theory Reason, the public art needs crowd to join that means its publicity more close to Practice Reason. As people attack Hegel that Absolute Spirit abandons its dialectic process, we should examine whether the publicity in public art abandons its public. In this thesis, we discuss two artworks in junior High School of “What is Happy?” and “Take a break”, the former made of montage images of teacher and student’s response, the latter is a mechanical instrument moving when the crowd steps into sensor area. They present that public art welcome its public without presumption, it’s content could change with anyone who joins it. What we explain rely on Lacan’s psychoanalysis theory, Lacan try to provide theory basis for psychoanalysis practice, that is the client has dialogue with the analyst seeking the Other in the other,. The client-analyst relationship forms the universal meaning field which make the client move outward the personal field. Lacan designated our way to Other is impossible, that inspires us still interacting with other and enriches our culture life. We follow the idea to redefine public art, it can attract people to appreciate and never get it’s end, because it plays the role of pure, empty art form.