英：counterpart; 法：semblable
从1930年代开始，“相似者”这一术语便在拉康的著作中扮演着一个重要的角色，它指的是主体知觉到同自身具有某种相似性（主要是视觉上的相似）的其他人。相似者在闯入情结 (intrusioncomplex)与镜子阶段 (MIRROR STAGE)中扮演着一个重要的角色（它们本身是密切相关的）。
闯入情结是拉康在其1938年关于家庭的文章中讨论的三个“家庭情结”之一，它发生在孩子首度认识到自己有兄弟姐妹，认识到像他一样 (like him)的其他主体也参与到家庭结构当中的时候。这里强调的重点在于相似性：孩子基于对身体相似性的识别而认同于自己的兄弟姐妹 (当然，此种相似性取决于主体与其兄弟姐妹之间较小的年龄差异)。正是此种认同造成了“相似者的意象”(Lacan, 1938:35-9)
相似者的意象同主体自己身体的形象是可以互换的，即主体在镜子阶段中与之认同的镜像 (SPECULAR IMAGE), 后者导致了自我的形成。此种可互换性明显存在于诸如互易感觉（TRANSTTIVISM)的现象之中，同时它也阐明了主体在其自我的基础上来建构其对象的方式。另一个人的身体的形象，只有就它在知觉上相似于某人自己的身体而言，才能被认同，而反过来说，只有通过把某人自己的自我投射到相似者的身上，相似者才能被当作一个分离的、可辨认的自我来加以识别。
在1955年，拉康引入了“大他者”与“小他者”(抑或“想象的他者”)之间的区分，把后一术语保留给了相似者和/或镜像。相似者之所以是小他者，是因为它根本不是真正相异的：它不是由大他者所代表的那种根本相异性，而是就其相似于自我而言的小他者(因此，L图式中的a与a'具有可互换性)。
(semblable) The term 'counterpart'plays an important part in Lacan's work from the1930s on, and designates other people in whom the subject perceives a likeness tohimself (principally a visual likeness). The counterpart plays an important part in theintrusion complex and in theMIRRORSTAGE (which are themselves closelyinterrelated).
The intrusion complex is one of the three 'family complexes'which Lacan discussesin his 1938 article on the family, and arises when the child first realises that he hassiblings, that other subjects like him participate in the family structure. The emphasis hereis on likeness; the child identifies with his siblings on the basis of the recognition ofbodily similarity (which depends, of course, on their being a relatively small agedifference between the subject and his siblings). It is this identification that gives rise tothe 'imago of the counterpart' (Lacan, 1938:35-9).
The imago of the counterpart is interchangeable with the image of the subject's ownbody, the SPECULAR IMAGE with which the subject identifies in the mirror stage, leading to the formation of the ego. This interchangeability is evident in such phenomena as TRANSITIVISM, and illustrates the way that the subject constitutes his objects on thebasis of his ego. The image of another person's body can only be identified with insofaras it is perceived as similar to one's own body, and conversely the counterpart is onlyrecognised as a separate, identifiable ego by projecting one's own ego onto him.
In 1955 Lacan introduces a distinction between 'the big Other'and 'the little other' (orthe imaginary other'), reserving the latter term for the counterpart and/or specular image. The counterpart is the little other because it is not truly other at all; it is not the radicalalterity represented by the Other, but the other insofar as he is similar to the ego (hencethe interchangeability of a and a'in schema L).