若哲學肯定真理是有意義的，那因為它是關於「實在」──存在的真實── 的真理。而精神分析之所以突出哲學的道路，就在於它主張關於真實這個空洞並 沒有這樣真理可言，因而對於不可能之真實只能有一種不知道的知識，也就是「無 意識的知識」。 拉岡指出真理是建立在意符的運作上，它本身未必需要以思想內容為基礎。 因此，真理必然是「我，真理，我說話」(Moi, la vérité, je parle.)，但它卻無被說 出、也無法被書寫下來。說話者和真理的關係並非他「擁有」或「沒有」真理， 而是他「並非沒有」(pas sans)真理。也因此，真理的本質超乎存有學的在與不在， 而只能處於海德格所稱的「揭蔽」(Unverbogenheit)向度中。而精神分析經驗正是 對於此種無法言說、書寫之不可能的真理的知識。

Given that the truth is about “the reality of being,” philosophy affirms that the truth is meaningful. In contrast to philosophy, psychoanalysis claims that such an absolute truth does not exist from a hole of the real. Therefore, in terms of the impossible real, the truth emerges through a kind of unknowable knowledge; that is, the “unconscious knowledge.” For Lacan, the truth is constructed by the operation of signifiers, and it does not necessarily emerge through thoughts. Thus, the truth is “I, the truth, I speak” (Moi, la vérité, je parle); it can neither be spoken nor be written down. Moreover, the speaking subject is either “having” or “not having” the truth; he is “not without having” (pas sans) it. In other words, the truth dismantles the binary opposition of “having” and “not having” at an ontological level. It dwells in the dimension of what Heidegger calls “unconcealment” (Unverbogenheit). And psychoanalytic experiences offer us an approach to the unspeakable and impossibly-writing knowledge.