本文藉由討論如何思考嬰兒的微笑，展開對當代心理學知識取徑的反省，並提供一個現象學考察的示範。當代心理學強調實徵上可驗證的 (empirically validated) 知識，但又對人類知覺經驗不信任，從而漠視了生活中的直接經驗，轉向理論的建構與驗證方法的設計，以做為有效知識的保障。本文指出，想要去除「主觀」經驗的努力並未真的保障了心理學知識地位，反而因為逃避不可避免的知覺經驗，使得當代心理學知識堆疊在更多可疑的預設之上。以嬰兒的微笑為例，本文回到嬰兒的微笑對我們給出的生活經驗中，讓此一熟悉但又模糊的現象之本質結構獲得明晰的勾劃(articulation)。本文獲得了這樣的認識：第一心理學知識層面不只一種，不同的方法有對不同層面知識的適切性。相較於以個體為單位的心理學知識層面，以偶連關係整體為單位的心理學知識層面更為原初，更少預設，也是本文以現象學方法考察對「嬰兒微笑」之經驗的所在層面。第二，在此知識層面裹，對「嬰兒的微笑」經驗的本質可以被揭露為一種將嬰兒與經驗者帶入同伴關係之中而雙方皆有所不同的形構作用。第三，本文也將思考延伸到偶連關係中的其他形構作用形式，如透露著精神分裂氣氛的「使為人之不能」的剝除形式；讓孩童經驗到「我被要求成為的」與「我所是的」之問差距的「強人所難」形式；以及以奪取對方的方式來獲得自己整體感的「奪取者－被奪取者」形式。

This article reflects upon the approach of contemporary mainstream psychology to knowledge and demonstrates a phenomenological alternative in terms of examining infants' smiles. Contemporary mainstream psychology on the one hand emphasizes empirically validated knowledge, yet on the other distrusts human perceptions. As a result, it ignores the direct experiences in everyday life and turns to theoretical construction and methodological validation for the promise of truth. This article, however, points out that the efforts to deprive “subjective” experiences do not guarantee a scientific value of psychological knowledge. On the contrary, the contemporary mainstream psychology takes on more suspicious assumptions as it tries to avoid the inevitable perceptional experiences. This article returns to lived experiences where the infants' smiles are given, and articulates the essential structure of such a familiar, yet ambiguous phenomenon. This article obtains the following understandings: first, there are two levels of psychological knowledge and each has its own appropriate methodology; one takes individual as the observation unit and the other takes coupling as the observation unit. The latter, more original and with less assumption than the former, is the methodology applied for exploring the phenomenon of experiencing infants' smiles. Second, on this level of knowledge, the experiences of infants' smiles can be understood as constituting moments in which the infants and their counterparts formulate a coupling relationship and thus become different respectively. And third, some extended examinations on the infant/child-adult coupling constitutions are also discussed in this article. They include the deprived mode of psychotic “letting unable to be,” the demanding mode that allows the child an experience of a gap between “what I am” and “what I should be,” and the “taking-taken” mode of taking away from each other in order to maintain one's own sense of completeness.