Topics are high-level in their aim. They are the general subject. Themes, what I sometimes call “angles,” are different. They’re targeted. They’re a subset of the larger subject at play.
For example, a topic is the housing market. A theme would be the effect of the housing market upon a specific group within a specific city, say the effect of urbanization upon the St. John community in Austin. The theme is still relatively broad and would need to be refined further depending on factors such as length. What I can say in 1,200 words is not the same as what I can say in 400. The one allows for expansion; the other requires a laser-like focus.
An additional factor is the publication itself. What works as a theme for The Statesman will not work for an arts and culture magazine. The theme has to be specific to the context in which it is placed, not to mention the editor who will be looking at it with her eagle eyes and ever-ready red pen.
Another consideration is the audience. While it may result in the same theme as brought about by a consideration of the publication, it will inevitably result in a different tone and style. I can get away with a chatty style with a younger audience. I probably will want to be more formal if I’m addressing the physicians who read The Statesman.
Why explore the difference between topics and themes? It’s important to understand that topics are nothing without their themes. A topic cannot be exhausted in 1,200 words; a topic can be a lifelong study. A theme, though, narrows the topic and brings verve, clarity, and cohesiveness to it.
Image: theilr (Creative Commons)