‌‌‌‌　　英：index; 法：indice

‌‌‌‌　　在北美符号学家查尔斯·桑德斯·皮尔斯所设想的符号 (SIGS)类型学中，指示符是与其所表征的对象具有“存在性关系”(existential relationship)的一种符号（即指示符总是在空间上或时间上临近于对象）。皮尔斯把指示符与“象征符”(symbol)对立起来，后者与索绪尔的符号概念一样，是以符号与其对象之间的所有必然联系的缺位为特征的。例如，烟是火的指示符，而红疹是诸如麻疹之类的各种疾病的指示符 (Peirce, I932).

‌‌‌‌　　在拉康的话语中，“指示符”一词与“能指”(SIGNIFIER)这一术语相对立 (而非是如同在皮尔斯的哲学中那样，与“象征符”这一术语相对立)而运作的。因而，拉康便把指示符构想为一种“自然符号”(nature sign),其中符号与对象之间是一种固定的一一对应关系 (不同于能指，能指与任何一个所指皆没有固定的联系)。指示符与能指之间的此种对立，支撑了拉康著作中的下列区分：

‌‌‌‌　　·精神分析与医学有关“症状”(SIMPTOM)的概念在医学中，症状被视作疾病的一个指示符，而在精神分析中，症状则不是一个指示符，而是一个能指 (E, 129)。因此，在精神分析中，病理性现象与潜在的结构之间便没有任何一对一的固定联系。

‌‌‌‌　　·（动物的）“编码”(CODE)与（人类的）语言编码是由指示符所组成的，而语言则是由能指所组成的。这便解释了编码为什么缺乏语言的最重要特征，即其潜在的歧义性与多义性。

‌‌‌‌　　能指与指示符之间的这一对立，由于某些同样充当指示符来运作的能指的存在而复杂了：这些充当指示符而运作的能指，即所谓的转换词(SHIFTERS)。

‌‌‌‌　　(indice) In the typology of SIGNS devised by Charles S.Peirce, the North Americansemiotician, the index is a sign which has an 'existential relationship'to the object itrepresents (i.e.the index is always spatially or temporally contiguous with the object). Peirce contrasts the index with the symbol, which, like Saussure's concept of the sign, ischaracterised by the absence of all necessary connections between the sign and its object. For example, smoke is an index of fire, and red blotches are an index of various diseasessuch as measles (Peirce, 1932).

‌‌‌‌　　In Lacan's discourse, the term 'index'functions in opposition to the term'SIGNIFIER' (and not, as in Peirce's philosophy, in opposition to the term symbol) Lacan thus conceives the index as a 'natural sign', one in which there is a fixed, bi-univocal correspondence between sign and object (unlike the signifier, which has nofixed link with any one signified). This opposition between index and signifier underpinsthe following distinctions in Lacan's work:

‌‌‌‌　　The psychoanalytic and medical concepts of the SYMPTOM Whereasinmedicine, the symptom is regarded as an index of the disease, in psychoanalysis thesymptom is not an index but a signifier (E, 129). Hence in psychoanalysis there is no one-to-one fixed link between pathological phenomena and the underlying structure.

‌‌‌‌　　CODES (animal) and language (human) Codes are composed of indices, whereaslanguage is composed of signifiers. This explains why codes lack the most importantfeature of language: its potential for ambiguity and equivocation.

‌‌‌‌　　The opposition between signifier and index is complicated by the existence of certainsignifiers which also function as indices; these are called SHIFTERS.