For example, a theme in urbanism

In the literature of the commons, there exists a well-known trope on tagging, “the ‘I’ and the ‘it,’” first advanced by urban sociologist Richard Sennett in his 1990 book, The Conscience of the Eye. Does a youngster spray painting a subway car in the Bronx see that subway car? Sennett recalled New York in the 1970s: “The scale of this graffiti was what made the first impression: there was so much of it. . . . The kids were indifferent, however, to the general public, playing to themselves, ignoring the presence of other people using or enclosed in their space. . . . Transgression and indifference to others appeared joined in these simple smears of self, and with a simple result. The graffiti were treated from the first as a crime.”Whereas a tagger just shouts “I,” the “it” expresses the presence of others, past, present, and future through the material forms and constraints of the city. There are limits to personalization. Working with external circumstances that result from the presence of others pushes you to a higher level, and that is an important aspect of urbanism.

The aggregate of these material expressions constrains each individual contribution. To Sennett, whose more recent work on craft affirms this outlook, an artist working in a civic capacity does indeed see this material commons and lets it shape his or her intentions and expressions, through which the city becomes a medium.

To sense a cultural accumulation can be the first step toward recognizing a commons. The mature tagger can see the city as the cumulative state of many people presenting themselves to one another. Acts of tagging can add to the understanding of the city as commons, rather than detract from it. For example, in an early instance of public awareness graffiti and ambient ecofeedback, Eve Mosher’s HighWaterLine (2007) chalked the 10-feet-above-sea-level contour through the most densely built parts of New York. No degree of augmented reality tagging has quite the impact of old-fashioned chalking.

Ideas of the commons often resurface in this inquiry. We must return to them with respect to networked urban resources, with respect to environmental history of information, and with respect to attention itself. They raise fundamental questions about civility, the distracted urban citizen, and the public good. You have seen there are many kinds of commons. For now, simply note how commons has become a pragmatic concept, and note how well tagging brings that up.