What is the difference between a thesis statement and a theme?
There are some very strong parallels between both themes and thesis statements. I think you will find there will be much in the way of responses to how each will be different. For my bet, I would like to think of themes as something that can be found in writing that expresses the intent of what the author is trying to show. Themes can be found in literature and other forms of writing where an idea is explored in a complex and intricate manner. Examples of themes can be courage, the quest for justice, the collision between equally desirable, but ultimately incompatible courses of action, or the notion of identity formation. These themes are proven from a base that is not purely evidential and argumentative, which differentiates them from a thesis statement. For example, when Homer explore the theme of equally desirable, but ultimately incompatible courses of action, he does not do so in a strictly linear and evidential manner. Rather, he shows us character who must endure such a theme and how it plays out is built within the development of the character. Hektor's character evolution is how we, as the reader, see Homer's theme develop.
In contrast to this, a thesis statement is something that is built through evidence, analysis, and persuasion. It seems to me to be more linear and directed than a theme. For instance, a thesis statement can be analytical, which analyzes an idea and deconstructs it through a paper. A thesis statement could also be persuasive, and it hopes to do so through evidence and analysis. The websites below give examples of thesis statements. I think I differentiate both concepts as a thesis statement trying to prove something, while a theme seeks to explore it.