Allow me to take a moment to rant a little. There are some common metaphors that are slowly but surely losing their meaning as people get them mixed up or use them to describe an ever broadening set of nouns. These metaphors are transparency and opacity. They are most often used to refer to processes and procedures, though lately I’ve seen them in all kinds of literature and used to describe everything from word definitions to philosophical ideas.
Here’s how they should work. Transparent processes are easy to understand. Opaque processes are not. Think of a box full of gears. If the box is transparent, you can see how the gears move and can therefore anticipate actions, think up changes to the process, and generally know what you’re dealing with. If the box is opaque, you can’t see any gears moving, so you have to guess how things might work.
This is why the metaphors get confusing when used to describe things that are not processes. If you’re talking about a thing (such as an idea), you might think, “If this idea were a physical thing, I’d want to be able to see it to understand it. Therefore I’d think it should be opaque, because you can’t see transparent things. If I can’t see this idea-thing I can’t understand it.” This makes sense but is not how the metaphor works. It just isn’t.
Here’s the rule: the transparency/opacity refers to an imaginary enclosure. If it’s transparent, you can see what’s going on inside the enclosure; if it’s opaque, you can’t. Transparency = understandable. Opacity = mysterious.