At the heart of today’s most successful and innovative companies is design. It’s a discipline that has the power to improve every aspect of our lives.

Design luminaries including Calvin Klein, Dieter Rams, and Norman Foster are schooling the US Supreme Court in the laws of design. They’re rallying behind Apple, in the first design patents case to be heard by the court in over a century.

In 2011, Apple sued Samsung for all its profits from sales of its Galaxy smartphone, arguing that the South Korean electronics company had willfully copied Apple’s patented rounded-corner front face, bezel, the look of its icon grid, and packaging of its devices. It won and was awarded nearly $1 billion in damages, but last year, Samsung appealed to lower the amount to $548 million. Now, it’s appealing again, arguing—among other things—that the reduced penalty is still excessive because design only played a small part in the Galaxy’s sales success.

Designers are not having it.

In a thundering defense of design’s vital importance to tech, on Aug. 4, 111 distinguished design experts filed an amicus curiae letter that’s essentially a crash course in design theory. It’s signed by many design luminaries, several of whom have had their own work counterfeited and copied for years: industrial designer Dieter Rams, Louis Vuitton artistic director Nicolas Ghesquiere, fashion designers Calvin Klein, Paul Smith, Bentley’s design chief Stefan Hans Sielaff, architect Norman Foster and typography idol Paula Scher. Many signatories have designed products for the world’s leading companies including AT&T, Coca-Cola, General Electric, Xerox and, yes, even Samsung.

Reuters/Kim Hong-Ji

The illustrated 36-page brief was spearheaded by Industrial Designers Society of America member Charles Mauro and contains distilled lessons for anyone interested in understanding design. Drawing on cognitive science, design history, marketing theory, and consumer technology, it explains two fundamental rules of contemporary design: Design is the most important element of a consumer product, and good design is vital to new technologies.

1. The design is the product

Brief of Amici Curiae 111 Distinguished Industrial Design Professionals and Educators in Support of Respondent Textbook case.

[A] product’s visual design becomes the product itself in the minds of consumers. Modern cognitive and marketing science verifies this fact. Two examples prove the point. First, the distinctive CocaCola bottle, which was designed and patented in 1915, helped the soft drink become the most widely distributed product on earth. A 1949 study showed that more than 99% of Americans could identify a bottle of Coke by shape alone, and customers routinely report that Coke tastes better when consumed from the patented bottle. The same is true for American automobiles. Henry Ford’s original Model T was notoriously unattractive. After General Motors created an Art & Colours department in the 1920s, GM permanently surpassed Ford in annual sales. Embracing industrial design eventually lead to huge U.S. economic growth, as car manufacturers discovered that without changing the underlying technology, engineering or functionality, they could create many different makes and models simply by changing the automobile’s shape, style and appearance. Today, design outranks all other considerations and is the driving force behind new car purchases.

2. Design is an essential bridge between technology and consumer

Design is particularly important for consumer products with complex technology. Cognitive science proves that a product’s visual design has powerful effects on the human mind and decision making processes, and eventually comes to signify to the consumer the underlying function, origin, and overall user experience of that product. Sight is overwhelmingly our strongest sense. In addition, the human brain recalls memories and emotions attached to visual stimuli for far longer than text or words. Because the brain does not separate the physical appearance of an object from its functions, a consumer’s subsequent exposure, experience, or knowledge of a product are cognitively mapped onto the product’s visual design such that the look of the product comes to represent the underlying features, functions, and total user experience.

The authors therefore conclude that Apple’s design patents protect not only certain details of the visual design, but the entire product itself:

When an infringer steals the design of a successful product, it captures the consumer’s understanding of what the product does and what the product means in addition to the emotional connections associated with the company’s brand.

Until the heated legal battles started, Apple was actually a customer of Samsung. It had outsourced the production of displays and microchips for the iPad to several companies in Asia, including Samsung.

The Supreme Court case Samsung v. Apple is scheduled for October.