英：drive; 法：pulsion; 德：Trieb
弗洛伊德的“冲动”(Ticb)概念是其性欲理论的核心。对于弗洛伊德而言，与其他动物的性生活相反，人类性欲的区分性特征，即在于它不受任何本能 (NSTINCT)的控制（本能的概念意味着与对象的一种相对固定且与生俱来的关系），而是由冲动来调节的，冲动不同于本能是因为它们是极其易变的，而且其发展的方式也取决于主体的生活史。
拉康坚持主张弗洛伊德在“冲动”(Trieb)与“本能”(nstinkt)之间的区分，他批评詹姆斯·斯特雷奇由于在《标准版》中用“本能”(instinct)一词来共同翻译这两个术语而抹消了这一区分（E, 301)。“本能”表示的是某种神话性的前语言的需要 (NEED),而冲动则完全脱离了生物学 (BIOLOGY)的领域。冲动之所以不同于生物性的需要，是因为它们永远都无法得到满足，而且它们的目标也不是旨在对象，而是永远环绕着对象。拉康指出，“冲动的目的”(Triebziel)并非抵达一个“目标”(goal: 最终目的地)，而是跟随它旨在环绕对象的“目的”(aim: 其道路本身)(S11,168)。因而，冲动的真正目的就并非是某种完全满足的神话性目标，而是旨在返回其循环的路径，而享乐的真正来源便是此一封闭环路的重复性运动。
拉康提醒他的读者们注意，弗洛伊德曾经将冲动定义为由四个不连续元素所组成的一个蒙太奇：压力、目的、对象与来源。因此，冲动不能被构想为“某种最终的给定，某种古老的、原始的东西”(S11,162); 它彻底是一种文化性与象征性的建构。拉康因而从冲动的概念里清空了弗洛伊德著作中对于热力学和水力学的持续参照。
拉康把冲动的这四个要素并入了自己有关冲动“环路”(circuit)的理论。在此一环路中，冲动源出自一个爱欲源区（eroge-nous zone), 环绕着对象，然后再返回到这个爱欲源区。此一环路是由三种语法学上的语态来构建结构的：
(1)主动语态：例如，看到 (to see);
(2)自反语态：例如，看到自己 (to see oneself);
(3)被动语态：例如，被看到 (to be seen)。
前两个时间（主动语态与自反语态）是自体情欲性的：它们缺乏一个主体。只有在第三时间（被动语态）上，即在冲动完成其环路的时候，才会出现“一个新的主体”（也就是说，在此一时间之前，是没有任何主体存在的；见：S11,178)。虽然第三时间是被动语态，但是冲动在本质上永远是主动的，这就是为什么拉康写道：第三时间不是“被看到”(to be seen)而是“让自己被看到”(to makeoneself be seen)。即便是像受虐狂这种理应是“被动性”的冲动相位也是包含主动性的 (S11,200)。这一冲动的环路是让主体得以僭越快乐原则的唯一方式。
弗洛伊德曾经声称，性欲是由若干部分冲动 (德：Partieltrieb; 英：partial drive)所组成的，诸如口腔冲动 (oral drive)与肛门冲动 (anal drive)等，每一种部分冲动都由一个不同的来源（即一个不同的爱欲源区）所指定。起初，这些组元冲动 (component drives)都是无序且独立地运作的 (即儿童的“多形性倒错”)，但是在青春期它们则开始在生殖器官的首位之下变得有组织并融合了起来 (Frud, 1905d)。拉康虽然强调所有冲动的部分本质，但是他在以下两点上不同于弗洛伊德。
(1)拉康拒绝这些部分冲动总是能够达到任何完整的组织或是融合的这样一种思想，他指出这种生殖区的首要性即便被达成，也始终是一个极度不稳定的事件。因而，他便挑战了由弗洛伊德之后的一些精神分析家们所提出的生殖冲动 (genital drive)的概念：各种部分冲动以一种和谐的方式完全被整合在这种生殖冲动之中。
(2)拉康认为冲动都是部分的，不是就它们是一个整体 (某种“生殖冲动”)的部分的意义而言，而是就它们只是部分地代表着性欲的意义而言；它们并不代表着性欲的繁殖功能，而仅仅代表着享乐的维度 (S11,204).
拉康鉴别出了四种部分冲动，即口腔冲动 (oral drive)、肛门冲动 (anal drive)、视界冲动 (scopic drive)以及祈灵冲动 (invocatorydive)。这些冲动中的每一种都是由一个不同的部分对象与一个不同的爱欲源区所指定的，如表1所示。
| | 部分冲动 | 爱欲源区 | 部分对象 | 动词 |
| --- | -------- | -------- | -------- | ---- |
| D | 口腔冲动 | 口唇 | 乳房 | 吮吸 |
| | 肛门冲动 | 肛门 | 粪便 | 排泄 |
| d | 视界冲动 | 眼睛 | 目光 | 看到 |
| | 祈灵冲动 | 耳朵 | 声音 | 听到 |
前两种冲动联系着要求，而后两种冲动则联系着欲望。
1957年，拉康在讨论欲望图解的语境下提出了公式 ($◇D)作为冲动的数元/数学型 (MATHEME)。这个公式应当读作：被画杠的主体相对于要求的关系，即面对着要求的坚持一这一要求持续存在而没有任何要维持它的有意识意向一主体便消隐了。
贯穿于弗洛伊德著作中有关冲动理论的各种重新阐述的一个恒定的特征，即在于一种基本的二元论。起初，此种二元论是根据一方面的“性欲冲动”(Sexualtriebe)与另一方面的“自我冲动”(Ichtriebe)或是“自我保存冲动”(Selbsterhaltungstriebe)之间的对立来构想的。这一对立由于弗洛伊德在1914一1920年逐渐认识到自我冲动本身也是性欲的而受到了质疑，从而便导致他根据生命冲动 (Lebenstriebe)与死亡冲动 (Todestriebe)之间的对立来重新概念化冲动的二元论。
拉康认为保留弗洛伊德的二元论是非常重要的，他拒绝荣格的一元论一荣格认为所有的精神力量都能够被化约为一种单一的精神能量的概念 (S1,118-20)。然而，拉康却更偏向于根据象征界与想象界之间的对立，而不是根据两种不同冲动之间的对立来概念化此种二元论。因而，对拉康而言，所有的冲动都是性冲动，而且每一种冲动都是一个死亡冲动 (DEATH DRIVE), 因为每种冲动都是过剩的、重复的，并且是最终具有破坏性的 (Ec, 848).
冲动与欲望 (DESIRE)有着密切的联系；两者皆起源于主体的领域，与生殖冲动截然相反，后者（倘若它存在的话）是在大他者的那一边找到其形式的 (S11,189)。然而，冲动又不仅仅是欲望的另一个名称：它们是欲望在其中得以实现的部分的面向。欲望是单一且未分化的，而冲动则是欲望的部分表现。
(pulsion) Freud's concept of the drive (Trieb) lies at the heart of his theory of sexuality. For Freud, the distinctive feature of human sexuality, as opposed to the sexual life ofother animals, is that it is not regulated by any INSTINCT (a concept which implies arelatively fixed and innate relationship to an object) but by the drives, which differ frominstincts in that they are extremely variable, and develop in ways which are contingent onthe life history of the subject.
Lacan insists on maintaining the Freudian distinction between Trieb ('drive') and Instinkt (instinct'), and criticises James Strachey for obliterating this distinction bytranslating both terms as 'instinct'in the Standard Edition (E, 301). Whereas 'instinct'denotes a mythical pre-linguistic NEED, the drive is completely removed from the realmof BIOLOGY. The drives differ from biological needs in that they can never be satisfied, and do not aim at an object but rather circle perpetually round it. Lacan argues that thepurpose of the drive (Triebziel) is not to reach a goal (a final destination) but to follow itsaim (the way itself), which is to circle round the object (S11,168). Thus the real purposeof the drive is not some mythical goal of full satisfaction, but to return to its circular path, and the real source of enjoyment is the repetitive movement of this closed circuit.
Lacan reminds his readers that Freud defined the drive as a montage composed of fourdiscontinuous elements: the pressure, the end, the object and the source. The drive cannottherefore be conceived of as 'some ultimate given, something archaic,primordial' (S11,162); it is a thoroughly cultural and symbolic construct. Lacan thus empties the conceptof the drive of the lingering references in Freud's work to energetics and hydraulics.
Lacan incorporates the four elements of the drive in his theory of the drive's 'circuit'. In this circuit, the drive originates in an erogenous zone, circles round the object, andthen returns to the erogenous zone. This circuit is structured by the three grammaticalvoices
1 The active voice (e.g.to see)
2 The reflexive voice (e.g.to see oneself)
3 The passive voice (e.g.to be seen)
The first of these two times (active and reflexive voices) are autoerotic: they lack asubject. Only in the third time (the passive voice), when the drive completes its circuit, does 'a new subject'appear (which is to say that before this time, there was no subject:
See S11,178). Although the third time is the passive voice, the drive is always essentiallyactive, which is why Lacan writes the third time not as 'to be seen'but as 'to makeoneself be seen'. Even supposedly 'passive'phases of the drive such as masochisminvolve activity (S11,200). The circuit of the drive is the only way for the subject totransgress the pleasure principle.
Freud argued that sexuality is composed of a number of partial drives (Ger. Partieltrieb) such as the oral drive and the anal drive, each specified by a different source (a different erotogenic zone). At first these component drives function anarchically andindependently (viz. The 'polymorphous perversity'of children), but in puberty theybecome organised and fused together under the primacy of the genital organs (Freud, 1905d). Lacan emphasises the partial nature of all drives, but differs from Freud on twopoints.
- Lacan rejects the idea that the partial drives can ever attain any completeorganisation or fusion, arguing that the primacy of the genital zone, if achieved, is alwaysahighly precarious affair. He thus challenges the notion, put forward by somepsychoanalysts after Freud, of a genital drive in which the partial drives are completelyintegrated in a harmonious fashion.
- Lacan argues that the drives are partial, not in the sense that they are parts of awhole (a 'genital drive'), but in the sense that they only represent sexuality partially; theydo not represent the reproductive function of sexuality but only the dimension ofenjoyment (S11,204).
Lacan identifies four partial drives: the oral drive, the anal drive, the scopic drive, and the invocatory drive. Each of these drives is specified by a different partialobject and a different erogenous zone, as shown in Figure 4.
The first two drives relate to demand, whereas the second pair relate to desire.
In 1957, in the context of the graph of desire, Lacan proposes the formula ($◇D) as the MATHEME for the drive. This formula is to be read: the barred subject in relation todemand, the fading of the subject before the insistence of a demand that persists withoutany conscious intention to sustain it.
Throughout the various reformulations of drive-theory in Freud's work, one constantfeature is a basic dualism. At first this dualism was conceived in terms of an oppositionbetween the sexual drives (Sexualtriebe) on the one hand, and the ego-drives (Ichtriebe) or drives of self-preservation (Selbsterhaltungstriebe) on the other. This opposition wasproblematised by Freud's growing realisation, in the period 1914-20, that the ego-drivesare themselves sexual. He was thus led to reconceptualise the dualism of the drives in terms of an opposition between the life drives (Lebenstriebe) and the death drives (Todestriebe).
Lacan argues that it is important to retain Freud's dualism, and rejects the monism of Jung, who argued that all psychic forces could be reduced to one single concept ofpsychic energy (S1,118-20). However, Lacan prefers to reconceptualise this dualism interms of an opposition between the symbolic and the imaginary, and not in terms of anopposition between different kinds of drives. Thus, for Lacan, all drives are sexual drives, and every drive is a DEATH DRIVE since every drive is excessive, repetitive, andultimately destructive (Ec, 848).
The drives are closely related to DESIRE; both originate in the field of the subject, asopposed to the genital drive, which (if it exists) finds its form on the side of the Other (S11,189). However, the drive is not merely another name for desire: they are the partialaspects in which desire is realised. Desire is one and undivided, whereas the drivess arepartial manifestations of desire.