In season 1, episode 3 of the television series “Star Trek: Discovery,” when faced with a particularly wicked problem the captain of the starship Discovery speaks these words: “Universal law is for lackeys; context is for kings.” I suspect that the writers of this show consciously crafted these words for quotability. They rise to the heights of wisdom that Star Trek occasionally reaches. When I heard these words, I quickly paused the show and ran to my computer to record them because they eloquently expressed an important truth that I’ve been teaching for many years. Simple rules can serve as guides for novices, but experts operate in the more subtle realm of context.

In my work in the field of data visualization, I teach many simple rules of thumb to encourage best practices, but I’m always careful to explain why these guidelines work. I encourage my students to root their decisions in a nuanced consideration of context, not in a simplistic algorithm. When you fully understand why good rules of thumb work well in general, you can identify specific situations when they don’t apply. In other words, you can break the rules when the situation demands it.

Good teachers help people think at the conceptual level, navigating nuance, not merely at the procedural level. We humans are capable of thinking that is more sophisticated than blind obedience to algorithms. Procedural knowledge (“If A happens, then do X; if B happens, then do Y; else do Z.”) exhibits little if any understanding. Conceptual knowledge, on the other hand, allows us to master context, the realm of kings. If you want to become an expert in data visualization (or an any other field), avoid teachers, books, and courses that say “Do it this way” without explaining why. Don’t settle for being a lackey when you can become a king.