Via Positiva (Addition) vs Via Negativa (Subtraction)

A comparison between improving a system by adding something and improving it by removing something. The subtractive perspective prompts attention to options that may otherwise be overlooked.

Addition and subtraction are two ways to change a system. The via negativa perspective asks whether removing an obstacle, burden, or harmful feature could help before adding another component. Research on design tasks suggests that people can overlook subtractive options, but this does not establish that subtraction is usually safer or more effective.

Compare the actual changes and their dependencies. Removing a step can reduce friction or eliminate an essential check; adding support can create needed capability or unnecessary burden. Consider an unchanged option as well. A useful decision preserves the function that matters and evaluates the consequences of both presence and absence.

When to use it

When repeated additions create complexity, an obstacle may be removable, or the change options have been considered too narrowly.

How it can help

Can expose removable burdens while requiring a check of the functions and dependencies that a removal would affect.