My recent piece entitled “Ignorance is Dangerous” was essentially an angry condemnation of ignorance and the ignorant. In that piece, however, I failed to adequately distinguish between many types of possible ignorance and levels of it, which is essentially my aim here.

The first distinction that must be made is one that is, at best, implicit in “Ignorance in Dangerous.” I think there are two distinct types of–which is to say causes of–ignorance. The essential distinction that must be made is between willful and necessary ignorance.

Willful ignorance is when someone actively chooses to be ignorant about a given topic. I am willfully ignorant of Star Trek, the details of Perez Hilton’s latest celebrity feuds, and the machinations of conspiracy theorists. Other may willfully choose to be ignorant about economics, politics, history, science, religion, or lemon cakes. Regardless of the topic, willful ignorances is a choice.

Necessary ignorance is quite different. One is necessarily ignorant about things which they have no ability to learn about. Necessary ignorance can take many forms. For one simple example, I’m necessarily ignorant of the realities of being a Turkish man living in Turkey, Germany, or Japan. Regardless of how hard I tried to be and know that, I never would understand it as it is lived. I could gain a superficial understanding through talking to Turkish men in those situations, but it would never be the same thing.

More relevantly, many people are kept in ignorance for lack of access. One example of lack of access is provide by China. In China, even if I were deeply interested in learning about the history of Tienanmen and democracy movements within the country, I would find it essentially impossible because the government makes every effort to assure that I cannot do so.

Cost can also be a border to access. Though libraries and relatively cheap access to the internet can nullify many cost obstacles, they still aren’t accessible for everyone in “the first world.” And that is to say nothing of people and places without even a hope of these amenities.

Another reason for necessary ignorance is lack of time. This can be a problem anywhere. If you’re a single mother with four children who has to work 40 hours or more a week just to make ends meet, there’s a good chance you’re completely unable to combat your ignorance about politics.

There is no hard-and-fast line between willful and necessary ignorance. There are certainly places where they blend together and it becomes hard to distinguish one from the other. Is a parent who works 40 hours a week and hardly finds any “alone time” after watching their children, doing the chores, and spending time with their spouse willfully ignorant of the situation in, say, Pakistan–after all, they could have spent less time with spouse and children to learn about it–or are they necessarily ignorant of it?

Regardless of the answer, we must also distinguish between various topics of ignorance. As I mentioned before, I’m relatively ignorant about Star Trek, but I know a fair amount more about world politics than your average Trek nerd. Though its easy to make value judgments about areas of ignorance, the point should be made that few people are universally ignorant. Chances are good that everyone has ignorances and areas of knowledge different from mine, this isn’t necessarily a problem.

In many ways, “Ignorance is Dangerous” was a result of my frustrations that my ignorances are different from those of others. Where I find ignorance of Paris Hilton perfectly excusable, others are deeply knowledgeable about her–either out of love or loathing.

Having said that, one could, and perhaps I did, argue that there are ignorances that are inherently more excusable than others. I consider knowledge of the human condition essential to living a good life, and public policy knowledge–at least of a rudimentary kind–similarly necessary. Knowledge of religions and the humanity of others are similarly important to me.

If I desire to promote those areas of knowledge, and make ignorance of them more difficult, there are number of ways forward. For one, efforts to end necessary ignorances are needed. These could take a number of forms: joining democracy movements to change closed societies and taking steps to eradicate poverty are just two examples.

In the area of willful ignorance, the path is less clear. For one, I think making clear to people that not all ignorance is necessary would help. Too often people think that they can’t learn something because they’ve never made an effort.

More noticeably, celebrities have immense power to make people interested in the things for which they’re passionate. Bono, Angelina Jolie, and Bill Gates are the first to spring to mind as examples of that, but I’ve heard that even Paris Hilton is trying to become involved in honorable charity work. And the passions of normal people can have a similar, if less widely noticeable, effect.

The fight against ignorance isn’t always easy, and the path isn’t always clear, but I’m pretty sure it’s a worthy effort.