Vignelli was a modernist designer of the old-school. This quote is from his manifesto, The Vignelli Canon (downloadable for free here).
In Vignelli’s view the goal of design was not the pursuit of beauty or self-expression, but the forensic application of guiding principles to every project. He saw design not merely as an intellectual process but as a severe, ascetic discipline. Using Swiss grids and a limited type palette – often only a single font per project, usually Helvetica – he constructed rigid, scaleable systems to drive every design decision, leaving no room for exploration or accidental discovery.
This approach led to a body of work that is austere, finely-balanced and entirely predictable. When function is the driving design principle – as to a New York subway rider – it’s perfect.
For everyone else, it’s a little bit boring.
Designers traffic in two main commodities: ideas (the concept phase) and execution (the design phase). Some of the best ideas arrive accidentally. This is why creative teams engage in blue sky thinking by brainstorming in caffeinated groups, looking for happy accidents by smashing disparate thoughts together like particles in a collider until something interesting pops out.
The same is true for execution. For every good idea there is an unlimited number of possible design solutions, and most of them you haven’t thought of yet. This is why designers engage in unguided “design exploration” by trying a lot of things quickly, throwing stuff at the wall – figuratively, but sometimes also literally – to see what new sparks emerge. Organized chaos is simply part of the process.
Happenstance is how new things are born. If your toolkit is limited to Helvetica and a Swiss grid, you can make a very effective design system – but you’ll miss out on the magic of discovery.