英：defence; 法：defense; 德：Abwehr
从弗洛伊德最早期的著作开始，他便把防御的概念定位于其神经症理论的核心。防御指的是自我针对某些被自我视作危险的内部刺激的反应。虽然弗洛伊德后来渐渐认为，除了压抑（REPRESSION)之外还存在很多不同的“防御机制”(见：Freud, 1926 d), 但是他也明确表示说，压抑在其构成无意识的意义上是独一无二的。安娜·弗洛伊德在她的《自我与防御机制》(The Egoand the Mechanisms of Defence)一书中曾试图对这些机制中的一些进行分类 (Anna Freud, 1936)。
拉康对于安娜·弗洛伊德与自我心理学解释防御概念的方式持极具批判性的态度。他认为他们把防御的概念混淆于阻抗（RESISTANCE)的概念 (Ec, 335)。出于这个原因，拉康在讨论防御概念的时候便显得相当谨慎，而且他也不愿把自己有关精神分析治疗的概念集中于防御。当拉康确实讨论到防御的时候，他都会使之与阻抗相对立；阻抗是对于象征界侵入的暂时的想象性回应，并且处在对象的一边，而防御则是主体性的更加持久的象征性结构 (拉康通常将其称作幻想[FANTASY]而非防御)。此种在阻抗与防御之间进行区分的方式截然不同于精神分析的其他学派，如果说这些学派真要在防御与阻抗之间做出区分的话，那么他们一般也都会把防御看作暂时的现象，而把阻抗看作更加稳固的现象。
欲望与防御之间的对立，对于拉康而言，是一种辩证的对立。因而，他在 1960 年指出，如同神经症患者一样，性倒错者也会“在自己的欲望上进行防御”，因为“欲望是一种防御 (defense), 是针对在享乐中超出某种界限的禁止(defense)”(E,322)。在1964年，拉康又继而声称：“欲望会涉及一个将其等同于不想要欲望的防御性阶段。”(S11,235)
(defense) From his earliest works, Freud situated the concept of defence at the heart ofhis theory of neurosis. Defence refers to the reaction of the ego to certain interior stimuliwhich the ego perceives as dangerous. Although Freud later came to argue that therewere different 'mechanisms of defence'in addition to REPRESSION (see Freud, 1926 d), he makes it clear that repression is unique in the sense that it is constitutive of theunconscious. Anna Freud attempted to classify some of these mechanisms in her book The Ego and the Mechanisms of Defence (1936).
Lacan is very critical of the way in which Anna Freud and ego-psychology interpretthe concept of defence. He argues that they confuse the concept of defence with theconcept of RESISTANCE (Ec, 335). For this reason, Lacan urges caution whendiscussing the concept of defence, and prefers not to centre his concept of psychoanalytictreatment around it. When he does discuss defence, he opposes it to resistance; whereasresistances are transitory imaginary responses to intrusions of the symbolic and are on theside of the object, defences are more permanent symbolic structures of subjectivity (which Lacan usually calls FANTASY rather than defence). This way of distinguishingbetween resistance and defence is quite different from that of other schools ofpsychoanalysis, which, if they have distinguished between defence and resistance at all, have generally tended to regard defences as transitory phenomena and resistances asmore stable.
The opposition between desire and defence is, for Lacan, a dialectical one. Thus heargues in 1960 that, like the neurotic, the pervert defends himself in his desire', since'desire is a defence (defense), a prohibition (defense) against going beyond a certain limitin jouissance' (E, 322). In 1964 he goes on to argue: To desire involves a defensivephase that makes it identical with not wanting to desire' (S 11,235).