Metaphors are a great language tool, because they explain the unknown in terms of the known. But they only work if they resonate in the heart of the writer. So I felt a little understaffed here, loving the metaphor when I came upon it, wanting to work with it, and yet not loving to garden.

Mission statements, synergies, strategies, visions—they are often ambiguous to the point of being meaningless. Naturally sticky ideas are full of concrete images —ice-filled bathtubs, apples with razors—because our brains are wired to remember concrete data. In proverbs, abstract truths are often encoded in concrete language: “A bird in hand is worth two in the bush.

For thousands of years, people have exchanged sound bites called proverbs. Proverbs are simple yet profound. Cervantes defined proverbs as “short sentences drawn from long experience.” Take the English-language proverb: “A bird in the hand is worth two in the bush.” What’s the core? The core is a warning against giving up a sure thing for something speculative. The proverb is short and simple, yet it packs a big nugget of wisdom that is useful in many situations.

Some analogies are so useful that they don’t merely shed light on a concept, they actually become platforms for novel thinking. For example, the metaphor of the brain as a computer has been central to the insights generated by cognitive psychologists during the past fifty years. It’s easier to define how a computer works than to define how the brain works. For this reason it can be fruitful for psychologists to use various, well-understood aspects of a computer—such as memory, buffers, or processors —as inspiration to locate similar functions in the brain.

Good metaphors are “generative.” The psychologist Donald Schon introduced this term to describe metaphors that generate “new perceptions, explanations, and inventions.” Many simple sticky ideas are actually generative metaphors in disguise. For example, Disney calls its employees “cast members.” This metaphor of employees as cast members in a theatrical production is communicated consistently throughout the organization:

• Cast members don’t interview for a job, they audition for a role.

• When they are walking around the park, they are onstage.

• People visiting Disney are guests, not customers.

• Jobs are performances; uniforms are costumes.

A metaphor is useful only for transforming what happens, enriching it in some way. It never tells you what actually happened, how it happened, or why it happened.