What is the difference between signifiers and classifiers?

The simple way of thinking about it is that classifiers allow for an object to only exist in one place, like a book on a shelf. Signifiers are more akin to shining a light, so are more intersectional, and allow for multiplicity. An object might have many signifiers, but only one classification.

Moreover signifiers are relative, classifications are absolute.

Are all classification systems are signifiers when examined close enough?

Say in the case of identity: are you just what you do, or a collection of different modalities you encountered — places you grew up, mood you woke up, and current coloring of thoughts? This is of course a function of the observer.

Back in our model – classifications only exist in the bottom–‘what am I’–section, where the top is made of signifiers, simply because it mostly happens in our head.


When we conjure up ideas we don’t care where they belong. They simply float from one rational axiom to another, until they accumulate enough weight to stand on their own feet, and then communicated through absolute terms and classifications, say in an email like the one you’re reading.

I should credit Alan Kay, who during a Skype interview last year, generously gave me this metaphor to articulate this idea (as well as my move from artifacts to systems by the way).

One of the things I talk about in talks is to ask people are ideas made out of matter or are ideas made out of light?

You can shine as many spots on the wall as you want and they all superpose, they all just sit there.

A designer is a person who tends to treat ideas as being like light.

—Alan Kay, October 2019, Skype Interview

March 13, 2020