From No Subject - Encyclopedia of Psychoanalysis
Jump to: navigation, search

Algebra is a branch of mathematics

  • which reduces the solution of problems to manipulations of symbolic expressions, and
  • concerned with the properties and relationships of abstract entities represented in symbolic form.

Algebra (French: algèbre) is a branch of mathematics which reduces the solution of problems to manipulations of symbolic expressions.

Formalisation can provide a core of psychoanalytic theory.

The formulae thus become a medium for the transmission of psychoanalytic knowledge.


Jacques Lacan begins to use algebraic symbols in 1955 (in an attempt to formalise psychoanalysis).

Jacques Lacan attempted to formalize psychoanalytic theory in terms of algebraic symbols.

Lacan used quasi-mathematical formulae in an attempt to set psychoanalysis on a more scientific footing.

Formalisation is necessary for psychoanalysis to acquire scientific status.

The algebraic symbols are to be used, manipulated and read in various different ways.[1]


The difference between upper- and lower-case symbols, the difference between italicised and non-italicised symbols, the use of the apostrophe, the minus sign, and subscripts.

For example the upper-case letters usually refer to the symbolic order, whereas the lower-case letters usually refer to the imaginary.

The use of the bar is also important.

His use of algebraic formulations is in fact unconnected to mathematics itself, but merely provides a concise way of expressing complex psychoanalytic concepts.

a generalization of arithmetic in which letters representing numbers are combined a branch of mathematics in which symbols, usually letters of the alphabet, represent numbers or members of a specified set and are used to represent quantities and to express general relationships that hold for all members of the set.

The algebraic symbols used by Lacan, which appear principally in the mathemes, schema l and the graph of desire, are listed below, together with their most common meaning.

The symbols do not always refer to the same concept throughout Lacan's work, but are used in different ways as his work develops.

Therefore some caution should be exercised when referring to the following list of equivalences.

Even other symbols which are relatively stable in meaning are occasionally used in very different ways.


A the big Other
A the barred Other
a (see objet petit a
a' (see objet petit a
BigS.gif 1. (before 1957) the subject
2.(from 1957 on) the signifier
3. (in the schemas of Sade) the raw subject of pleasure
StrikeS.gif the barred subject
SS1.gif the master signifier
SS2.gif the signifying chain/knowledge
s the signified (in the Saussurean algorithm
StrikeS(A).gif the signifier of a lack in the Other
S(a).gif the signification of the Other (the message/symptom)
D Demand
d Desire
m the ego (moi)
i the specular image (schema R)
i(a) 1. the specular image (graph of desire)
2. the ideal ego (optical model)
I the ego-ideal (schema R)
I(A) the ego-ideal (graph of desire)
Π the real phallus
Φ the symbolic phallus [upper-case phi]
(-φ) the imaginary phallus [lower-case phi]
S the symbolic order (schema R)
R the field of reality (schema R)
I the imaginary order (schema R)
P the symbolic father / Name-of-the-Father
p the imaginary father
M the symbolic mother
J Jouissance
phallic jouissance
JA the jouissance of the Other
E the statement
e the enunciation
V the will-to-enjoy (volonté de jouissance)


  1. Lacan, Jacques. Écrits: A Selection. Trans. Alan Sheridan. London: Tavistock Publications, 1977. p.313

See Also