Good, that's how it should be. You should always have some sort of backing for what you write, otherwise the conversation is meaningless; we then argue definitions as opposed to any formal material.
However, and despite me largely disagreeing with most of what people have said about planning pieces in this thread (even though I don't personally plan pieces), if you're using these theoretical, precompositional exercises out of fear (I use this term loosely; I don't think you're actually literally "afraid") or in preparation of theory-based criticism, you may be in the wrong headspace when it comes to using theoretical "justifications".
Rather, they should be your sword, not your shield. Even if you happen upon an interesting motive in your writing unintentionally, you can understand why you processed and wrote it as such; that is to say, the theory is able to be used in moment-to-moment composition, as opposed to a restriction in any short-scale form.