Many objects serve multiple purposes. This is often strived for in the name of efficiency. An object serving two purposes will sometimes do so simply by means of reciprocal actions. For example, a needle & syringe can put drugs into you or draw your blood, depending on the direction of the plunger.

One rule that can always be counted on to hold true: the number of purposes served by an object is a function of the number of layers under consideration, where the maximum number of purposes served corresponds to all layers being considered. To illustrate what I mean: inside a mechanical pencil, approx. two thirds of the way down, the shallow-sloped and funnel-shaped base of the lead chamber facilitates lead pieces being drawn into a shaft. Zooming out to the next layer reveals that this funnel-shaped base is part of a larger mechanism serving the purpose of advancing the lead bit by bit. zooming out again, additional served purposes are added to the list: a mechanical pencil can be used to write, draw, solve math problems, erase, etc.

Since increasing the number of purposes served by an object means adding layers to it, for many years the trade-off of serving more purposes was that the object was physically more complex and/or larger. The advent of computers and software has changed things a little. With digital systems, increased physical complexity isn’t nearly as relevant as increased computational complexity, and the trade-off isn’t size but power consumption and longer time requirements.

What happens when an object serves two purposes, one that is tied to cultural subjectivity and one that isn’t? A winter hat with a sports team logo embroidered on it might signal to passersby that the person wearing it is a big fan of the team, whereas the wearer may be more interested in simply keeping their ears warm and couldn’t care less about the logo.