英：identification; 法：identification; 德：Identifizierung
在弗洛伊德的著作中，“认同”这个术语是指某一主体借以将另一主体的一种或更多属性纳为己有的过程。在其后来的著作中，随着弗洛伊德又发展出了自我与超我均是基于一系列的认同而建构起来的思想，认同的概念便最终开始表示“人类主体借以构成的运作本身”(Laplanche and Pontalis, 1967:206)。因而，它是在精神分析理论中具有核心重要性的一个概念。然而，它也同样是引发了重要理论性难题的一个概念。这些难题中最重要的一个，也是弗洛伊德自己与之斗争的一个，便是在认同与对象爱恋 (object-love)之间建立明确关系的困难。
认同的概念在拉康的著作中占据着一个同等重要的位置。拉康特别强调形象的角色，他把认同定义为“当主体承担一个形象时在主体身上所发生的转变”(E, 3)。“承担”(assume)一个形象，即在那一形象中再认其自身，并且将那一形象当作其自身，据为己有。
从其早期的著作中开始，拉康便在想象性认同 (imaginary i-dentification)与象征性认同 (symbolic identification)之间做出了区分：
(1)想象性认同是自我在镜子阶段 (MIRROR STAGE)中借以被创造出来的机制，它绝对属于想象秩序。当人类幼儿看见自己在镜中的映像时，它便会认同那一形象。自我经由认同某种外在于（甚至是对立于）主体的事物而建立，这便“把主体结构成了他自己的竞争对手”(E, 22)且涉及了侵凌性与异化。镜子阶段构成了“原初认同”(primary identification),并且诞生了理想自我 (DEAL EGO).
(2)象征性认同是在俄狄浦斯情结 (OEDIPUS COMPLEX)的最后阶段对于父亲的认同，它引起了自我理想 (EGO-IDEAL)的形成。正是凭借这种次级认同 (secondary identification),主体才得以超越原初认同中所固有的那种侵凌性 (E, 23), 因而可以说是代表着某种“力比多的正常化”(libidinal normalisation)(E, 2)。尽管这一认同被称作“象征性”的，然而它作为一种“次级认同”（E, 2), 仍旧是以原初认同为模型的，因而像所有的认同一样带有想象性：它之所以被称作“象征性”的，仅仅是因为它代表着主体完成了进入象征秩序的通路。
拉康有关象征性认同之本质的思想，在他的著述过程中经历了一些复杂的改变。在1948年，他根据“对于同性父母意象 (imago)的内摄”来看待它 (E, 22), 而到了1958年，他则转向根据在俄狄浦斯情结的第三时间上对于实在的父亲的认同来看待它。
在1961年，拉康又继而把象征性认同描述为一种对于能指的认同。他以弗洛伊德在《群体心理学与自我的分析》(reud, 1921c: Group Psychology and the Analysis of the Ego)第七章中提出的三种认同的类目来佐证这一思想。在前两种认同 (认同爱恋对象，或是认同竞争对手)之中，主体表现认同的方式往往都可能只是发展出与其认同对象的症状相同的一个症状。在这样的情况下，“认同便是部分的且极其有限的，而且也只是从认同对象本人身上借取一个单一特征 (德：nur einen einzigen Zug)”(Freud, I92lc: SEXVI, l07)。此种“单一特征”(single trait, 在法文中是“traitunaire”，拉康的英文译本将其多样化地译作“实线”[unbrokenline]、“一划”[single-stroke]或是“单一特征”[unitary trait])被拉康看作将其内摄便会产生自我理想的一种原始的符号项。虽然此一特征可能原本是一个符号，但是当它被并入一个能指系统的时候却变成了一个能指 (S8,413-14)。在1964年，拉康又将单一特征联系于第一个能指 (S,),并且将它比作原始人为表示自己杀掉了一只动物而划在一根木棍上的刻痕 (S11,141,256).
拉康坚决反对那些宣称认同分析家便是分析的结束（END OF ANALYSIS)的作者 (例如：巴林特)；相反，拉康不但坚持“跨越认同的层面是可能的”(S11,273), 而且他还强调这对于真正的精神分析而言是一个必要的条件。因而，分析的结束便被拉康构想为主体的空乏，主体的认同在此一时刻上统统会受到质疑，如此以至于这些认同不再能够按照以前的方式来维持。然而，虽然分析的结束明确不是对于分析家的认同问题，但是拉康也指出在一种不同的意义上来谈论分析结束时的认同是可能的，即对于症状的认同 (见：圣状[SINTHOME])。
(identification) In Freud's work the term 'identification.'denotes a process whereby onesubject adopts as his own one or more attributes of another subject. In his later work, as Freud developed the idea that the ego and the superego are constructed on the basis of aseries of identifications, the concept of identification eventually came to denote 'theoperation itself whereby the human subject is constituted' (Laplanche and Pontalis, 1967:206). It is thus a concept of central importance in psychoanalytic theory. However, it is also a concept which raises important theoretical problems. One of the mostimportant of these problems, which Freud himself struggled with, is the difficultyofestablishing the precise relationship between identification and object-love.
The concept of identification occupies an equally important position in Lacan's work. Lacan places a special emphasis on the role of the image, defining identification as 'thetransformation that takes place in the subject when he assumes an image' (E, 2). Toassume'an image is to recognise oneself in the image, and to appropriate the image asoneself.
From early on in his work, Lacan distinguishes between imaginary identification andsymbolic identification.
- Imaginary identification is the mechanism by which the ego is created in theMIRROR STAGE; it belongs absolutely to the imaginary order. When the human infantsees its reflection in the mirror, it identifies with that image. The constitution of the egoby identification with something which is outside (and even against) the subject is whatstructures the subject as a rival with himself (E, 22) and thus involves aggressivity andalienation. The mirror stage constitutes the 'primary identification', and gives birth to the IDEAL EGO.
- Symbolic identification is the identification with the father in the final stage of theOEDIPUS COMPLEX which gives rise to the formation of the EGO-IDEAL. It is bymeans of this secondary identification that the subject transcends the aggressivityinherent in primary identification (E, 23), and thus can be said to represent a certain'libidinal normalisation' (E, 2). Although this identification is called 'symbolic', it is stilla 'secondary identification' (E, 22) modelled on primary identification and thus, like allidentification, partakes of the imaginary; it is only called 'symbolic'because it representsthe completion of the subject's passage into the symbolic order.
Lacan's ideas on the nature of symbolic identification undergo complex changesduring the course of his work. In 1948 he sees it in terms of the 'introjection of the imagoof the parent of the same sex' (E, 22), whereas by 1958 he has moved on to seeing it interms of the identification with the real father in the third time of the Oedipus complex.
In 1961, Lacan goes on to describe symbolic identification as an identification withthe signifier. He finds support for this idea in the catalogue of three types of identificationwhich Freud presents in chapter seven of Group Psychology and the Analysis of the Ego (Freud, 1921c). In the first two types of identification (with a love object or with a rival), the subject may often express the identification purely and simply by developing asymptom identical to the symptom suffered by the person with whom he identifies. Insuch cases,'the identification is a partial and extremely limited one and only borrows asingle trait /nur einen einzigen Zug/from the person who is its object' (Freud, 1921c: SEXVIII, 107). This 'single trait' (in French, trait unaire-which English translations of Lacan render variously as 'unbroken line','single-stroke'or 'unitary trait') is taken by Lacan to be a primordial symbolic term which is introjected to produce the ego-ideal. Though this trait may originate as a sign, it becomes a signifier when incorporated into asignifying system (S8,413-14). In 1964, Lacan links the single trait to the first signifier (S1), and compares it to the notch that primitive man made on a stick to signify that hehad killed one animal (S11,141,256).
Lacan is firmly opposed to those writers (e.g.Balint) who claim that identificationwith the analyst is the END OF ANALYSIS; on the contrary, Lacan insists not only that'the crossing of the plane of identification is possible' (S11,273), but also that this is anecessary condition of true psychoanalysis. Thus the end of analysis is conceived of by Lacan as the destitution of the subject, a moment when the subject's identifications areplaced under question in such a way that these identifications can no longer bemaintained in the same way as before. However, while the end of analysis is precisely nota question of identification with the analyst, Lacan argues that it is possible to speakabout identification at the end of analysis in a different sense: identification with thesymptom (see SINTHOME).