What do different kinds of theories look like?

: "everything fits together and is based on the same underlying principles"
: "everything is connected in some way or another"
: "this is what happened/happens"
: "these postulates form the basis of our understanding"

Opinions?

Examples (more are needed):

: Socionics, memetics
: Freud's theories
: Darwin's theory (not Darwinism, but Darwin's theory as expounded by Darwin himself)
: Socionics to some degree