Sign and Object

Object: represents an object on the basis of a potential resemblance

but without physical relation.

p.e. a photo or a drawing

Index: represents an object on the basis of a physical relation

p.e. smoke as a sign of the object fire

windvaan as the sign of the object wind

Symbol: represents an object on the basis of a general rule

p.e. ja of nee knikken, wetenschappelijke literatuur