The Law of Complementarity

George Spencer-Brown –the creator of a very original “logic of distinctions”—wrote an interesting statement about the Law of Complementarity:

“There is no stronger mathematical law than the law of complementarity. A thing is defined by its complement, i.e by what it is not. Ant its complement is defined by its uncomplement, i.e. by the thing itself, but this time thought of differently, as having got outside of itself to view itself as an object,. i.e. ‘objectively’, and then gone back into itself to see itself as the subject of its object, i.e. ‘subjectively’ again.” (See: George Spencer-Brown, Preface to the fifth edition of “Laws of Form” – First edition by Allen & Unwin, London, 1969)

When looking at the modal square formed by the articulation of Person, Subject, Agent and Object, the Person modality appears in the quadrant corresponding to the abstract-subjective. This result can be understood only in the terms suggested by Spencer-Brown, that is as a re-entry of the subjective into the objective.