Ignacio Matte Blanco hypothesized the nature of unconscious logic, as opposed to conscious logic. He deduced that if the unconscious has consistent characteristics it must follow rules, or there would be chaos. However the nature of these hypothetical characteristics indicates that their rules differ from conventional logic.

Ignacio Matte Blanco, The Unconscious as Infinite Sets: An Essay in Bi-logic, Routledge, 1981.
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A systematic effort to rethink Freud's theory of the unconscious, aiming to separate out the different forms of unconsciousness. The logico-mathematical treatment of the subject is made easy because every concept used is simple and simply explained from first principles. Each renewed explanation of the facts brings the emergence of new knowledge from old material of truly great importance to the clinician and the theorist alike. A highly original book that ought to be read by everyone interested in psychiatry or in Freudian psychology.


'Perhaps the first systematic effort to rethink Freud's theory of the unconscious, aiming to separate the different forms of unconsciousness (many of which Freud lumped into the concept of the "primary process") has been undertaken by Ignacio Matte Blanco in The Unconscious as Infinite Sets. Matte Blanco's work is of truly profound significance.'- Christopher Bollas


'Those [who have not read] The Unconscious as Infinite Sets are in for a very great treat.'- James S. Grotstein, M.D.


'A large volume probing the deeper aspects of psychology. Its charts of terra incognita are as good as any we yet have available.'- Karl Pribram, Journal of Nervous and Mental Diseases


'The logical-mathematical treatment of the subject is made easy because every logical-mathematical concept used is simply explained from first principles. Each renewed explanation of the facts brings the emergence of new knowledge from old material of truly great importance to the clinician and the theorist alike.'- Henri Rey, International Journal of Psychoanalysis


'This is a highly original book. The author, a professor of psychiatry who is a practicing psycho-analyst, feels that psycho-analysis needs a new theoretical frame of reference, without which it is proving impossible to see new facts in clinical reality. This book ought to be read by everyone interested in psychiatry or Freudian psychology.'- British Book News


Matte Blanco's hypothesis proposes that in the unconscious "a part can represent the whole" and that "past, present, and future are all the same"'. He set out to examine the five characteristics of the unconscious that Freud had outlined: timelessness, displacement, condensation, replacement of external by internal reality, and absence of mutual contradiction. Matte Blanco hypothesized the nature of unconscious logic, as opposed to conscious logic. He deduced that if the unconscious has consistent characteristics it must follow rules, or there would be chaos. However the nature of these hypothetical characteristics indicates that their rules differ from conventional logic.
In his work The Unconscious as Infinite Sets, Matte Blanco proposes that the structure of the unconscious can be summarised by the principles of Generalisation and of Symmetry: 1) The principle of Generalization: here logic does not take account of individuals as such, it deals with them only as members of classes, and of classes of classes. 2) The principle of Symmetry: here the logic treats the converse of any relation as identical to it; that is, it deals with relationships as symmetrical'.
While the principle of Generalisation might be compatible with conventional logic, discontinuity is introduced by the principle of Symmetry under which relationships are treated as symmetrical, or reversible. Whereas asymmetrical thinking distinguishes individuals from one another by the relationship between them, reality testing, symmetrical thinking, by contrast, sees relations as holding indiscriminately across a field of individuals. For example, an asymmetrical relationship, X is greater than Y, becomes reversible so that Y is simultaneously greater and smaller than X. Matte Blanco draws here on Klein's understanding that "I am angry (with a person or thing)" as very close to "Someone or something is very angry with me"; and indeed he suggests that Klein was the most creative and original of all those who have drawn inspiration from Freud, highlighting in particular her famous concept of projective identification.
For Matte Blanco, "unconsciousness" is marked by symmetry, where there is a tendency towards 'sameness' and likewise, an implicit aversion to 'difference', while the quality of ego-functioning registers and bears difference, in a sense he called asymmetry .
Matte Blanco divided the unconscious into two modes of being: the symmetrical and the asymmetrical. Asymmetrical relations are relations that are non reversible. For example, “Jack reads the newspaper” cannot be reversed to the newspaper reading Jack. In this way, asymmetrical relations are logical relations and underlie everyday logic and common sense. They govern the conscious sphere of the human mind. Symmetrical relations, on the other hand, move in both directions simultaneously. For example, 'Daniel sits on a stone' can be reversed as, 'a stone sits on Daniel', without being untrue. Symmetrical relations, govern the unconscious mind. Matte Blanco states that the symmetrical, unconscious realm is the natural state of man and is a massive and infinite presence while the asymmetrical, conscious realm is a small product of it. This is why the principle of symmetry is all-encompassing and can dissolve all logic, leading to the asymmetrical relations perfectly symmetrical.
To show the illogical nature of symmetry, Matte Blanco said: "In the thought system of symmetry, time does not exist. An event that occurred yesterday can also occur today or tomorrow. Traumatic events of the past are not only seen in the unconscious as ever present and permanently happening but also about to happen." He said that "We are always, in a given mental product, confronted by a mixture of the logic of the unconscious with that of the preconscious and consciousness". Matte Blanco gives this mixture of two logics the name bi-logic and points out that our thinking is usually bi-logical, expressing the both types of logic to differing extents. Matte Blanco saw in-depth analysis of the mind as falling into five broad strata: in which there is a particular combination of symmetrical and asymmetrical logic' appropriate to each one. In what he terms the first stratum, experience is characterized by the conscious awareness of separate objects. At this level thinking is mostly delimited and asymmetrical — closest to "normal", everyday life, to what W. R. Bion termed the mind of the "work group"...anchored to a sophisticated and rational level of behaviour. A second stratum can be defined by the appearance of a significant amount of symmetrization within otherwise asymmetrical thinking, so that for example a man in love will attribute to the beloved young woman...all the characteristics of the class of beloved woman, but (bi-logically) he will realize that his young woman also has limitations and defects.
The next deeper, third stratum is one where different classes are identified (thus containing a fair amount of asymmetrical thinking) but in which...parts of a class are always taken as the whole class — symmetrization (plus a degree of timelessness). The fourth stratum is defined by the fact that there is formation of wider classes which are also symmetrized, while asymmetry becomes less and less. Thus because "being a man" is a wider class than ones men, women and children, being a man is also equivalent to being a woman and a child. In this fourth and rather deep stratum, a number of the features of the Freudian unconscious are also characteristic. There is an absence of contradiction, also an identity of psychical and external reality. Finally, the deepest, fifth stratum is that in which processes of symmetrization tend towards the mathematical limit of indivisibility thinking, which requires asymmetrical relations, is greatly impaired and becomes the realm of psychotic functioning: without asymmetrical logic, play breaks down into delusion.
Normal human development for Matte Blanco, involved gradual familiarity with all five strata, including the capacity both to differentiate and to move between them all; in abnormal states, this continuity of differentiation between the strata becomes fractured or confused.
Thus, asymmetrical thoughts are said to be at the surface, while the symmetrical relations make up multiple lower strata that go deeper until an “invisible mode” or total symmetry is reached. In the deeper, completely unconscious levels, a statement such as “Jane is the mother of Jasmine” is equally valid as “Jasmine is the mother of Jane”. This statement reversal sounds preposterous to logical, asymmetrical, conscious thought, but the depth of the unconscious has its own rules. There, such a statement is true and incontestable. In this way, the principle of symmetry changes the asymmetrical to symmetrical or, put another way, the logical into the illogical.- wikipedia






Ignacio Matte Blanco, Thinking, Feeling, and Being, Routledge, 2003.

Ignacio Matte-Blanco has made one of the most original contributions to psychoanalysis since Freud.
In this book, which includes an introductory chapter to his work by Eric Rayner and David Tuckett, he develops his conceptualization of the Freudian unconscious in terms of logic and mathematics, giving many clinical examples.




Mathematical thought in the light of Matte Blanco's work (pdf)



Eric Rayner, Unconscious Logic: An Introduction to Matte Blanco's Bi-Logic and Its Uses, Routledge, 2003.


While the theories of Matte Blanco about the structure of the unconscious and the way in which it operates are generally recognised to be the most original since those of Freud, for many people the ways in which his ideas are expressed, including the use of terminology from mathematics and logic, make them difficult of access.Eric Rayner has written the first clear introduction to Matte Blanco's key concepts for psychotherapists and psychoanalysts and all those concerned with moving psychoanalytic thinking forward. He sets out the central ideas in a way which is easy to understand and then shows, with examples, how they relate to clinical practice. He also describes how the ideas are related to those of people in other disciplines - mathematics, logic, psychology (specifically Piaget), and anthropology, among others.
Drawing on the work of a group of people who have been inspired by Matte Blanco's thinking to extend their own ideas and test them out in the consulting room, this book reveals the significance of Matte Blanco's thought for future research.



"Now at last we have a good introduction to Matte Blanco's ideas written by Eric Rayner which makes this very different psychoanalytic perspective relatively easy to understand. He explains new concepts step by step but, more importantly, he gives many clinical illustrations of logical ideas. But firstly, who is Matte Blanco?" - British Journal of Psychotherapy
"... let me say that Unconscious Logic is a very good introduction to Matte Blanco's bi-logic. The psychotherapist nervous of logic may find that they understand much more logic than they thought. But more than this they will find in bi-logic a method of connecting diverse discilplines as well as a new approach to clinical material." - British Journal of Psychotherapy


Ignacio Matte Blanco was a Chilean psychiatrist and psychoanalyst who developed a rule-based structure for the unconscious which allows us to make sense of the non-logical aspects of thought. Born in Santiago, Chile, Matte Blanco was educated in Chile, and before leaving Chile for London, was in analysis with Fernando Allende Navarro, Latin America's first qualified psychoanalyst. He trained [in psychiatry] at the Maudsley Hospital and in psychoanalysis at the London Institute, where he was in supervision with Anna Freud and James Strachey, becoming a member of the British Society in 1938. He subsequently worked in the United States, Chile, and Italy, where his family now lives. He died in Rome at the age of 86.