Recently I have been thinking more abstractly about what Agile is, and why (or whether) it is good. The first thing I have discovered is that I was not, in fact, following Agile's practices, but Scrum's!
The difference between the two is less subtle than I thought.
According to the Scrum guide, Scrum consists of "roles, events, artifacts, and the rules that bind them together. [...] Scrum’s roles, artifacts, events, and rules are immutable and although implementing only parts of Scrum is possible, the result is not Scrum."
That is, Scrum has rigid rules which cannot be broken, mandatory meetings with strict time limits, and long lists of responsibilities for each role.
According to the Agile Manifesto, Agile is a short list of four value judgments.
That is, Agile lets you make your own decisions, but leads you in the right direction by (1) emphasizing the important goals, and (2) reminding you that achieving those goals may require you to sacrifice other goals.
Clearly, Agile is much more flexible than Scrum, while Scrum is much more complete and precise. Since I like to tweak my workflow from iteration to iteration, I think Agile is more appropriate for me.
Surprisingly, Agile by itself doesn't even mandate the work to be divided into iterations, and neither of them requires the work to be divided into stories! So... whose recommended practices have I been following, then?
I feel like there is a third contender which I have yet to discover.