Joseph Goguen gave seven dogmas in his paper A Categorical Manifesto.

- To each species of mathematical structure, there corresponds a
**category**whose objects have that structure, and whose morphisms preserve it. - To any natural construction on structures of one species, yielding structures of another species, there corresponds a
**functor**from the category of the first species to the category of the second. - To each natural translation from a construction
*F*:*A*->*B*to a construction*G*:*A*->*B*there corresponds a**natural transformation***F*=>*G*. - A
**diagram***D*in a category*C*can be seen as a system of constraints, and then a**limit**of*D*represents all possible solutions of the system. - To any canonical construction from one species of structure to another corresponds an
**adjuction**between the corresponding categories. - Given a species of structure, say widgets, then the result of interconnecting a system of widgets to form a super-widget corresponds to taking the
**colimit**of the diagram of widgets in which the morphisms show how they are interconnected. - Given a species of structure
*C*, then a species of structure obtained by “decorating” or “enriching” that of*C*corresponds to a**comma category**under*C*(or under a functor from*C*).

Although category theory is all about general patterns, it can be hard to learn what the general patterns of category theory are. The list above is the best high-level description of category theory I’ve seen.

**Related**: Applied category theory

“adjunction” ?

Yes, Google cannot define” adjuction.”