BLT's basic unit for thinking is known as a zygo. Zygo means pair or union. The term is derived from the Ancient Greek word ζυγόν (zugón) meaning yoke. Examples include Big-Little, Subjective-Objective, and Literal-Symbolic.
Synonyms for zygo include words like pair, dyad, polarities, binary, and opposites. However, the word Zygo denotes the many possible ways of conceptualising a pair (e.g. poles of a spectrum, binary opposites) and relating the parts of a pair (e.g. complements, opposites).
A useful metaphor is the concept of a Zygote - a term that simultaneously relates to one thing (a fertilised egg), two things (egg and sperm), and the potential to grow into multiple things. Accordingly, BLT encourages both-and-either-or-neither-nor and in-between ways of knowing and exploring problems.
Not all zygos are the same. An important aim of BLT is to facilitate better understanding of the nature, types and combinations of pairs that create and reflect our ways of thinking about the world.
Zygo: A conceptual pair with a contiguous and interdependent relationship (e.g. Active-Passive) whose constituents can be related in context as both-and-either-or-neither-nor and in-between.
Proto Zygo: A zygo that expresses all related zygos (e.g. Yin-Yang, Left-Right, Masculine-Feminine).
Symbolic Zygo: A contextualised pair that is used to express deeper structural zygos (e.g. Cats-Dogs, Fire-Ice, Sugar-Spice).
Triadic Zygo: A pair with a common connecting element (e.g. Black-Grey-White; Past-Present-Future)