Amy:
«Ant, I think you need to reread GG's post.
After "I thought," do NOT use the simple present tense.»
I have read this commandment (sic!) about a million times in about a hundread threads, and all that in the past two or three days. In my previous post I didn't call it in question. Rather, I tried to devise a logical explanation for it. (skip the mess below)
1. A thought is something with a finite lifespan. For example, if I am no longer thinking my cat is coward, this thought has disappeared into non-existance.
2. Therefore, by saying "I thought..." I am referring to a past thought of mine and may not use Present Simple for it would contradict with the thought's being "dead".
3. However, in reported speech in focus is not a thought but only a manifestation of a thought. In a way, such a manifestatin is eternal and "lives" as the information of it's having been utterd exists (on any type of medium, from the brain to the book). This makes the act of speech less connected to its parental thought. For example, a thought may have a lot of manifestatins issued at different times.
4. "He said the Earth is round" — these words refer to a so called general truth, which is nothing else than a long-existing thought supported/shared by many people. So, why not refer to a past manifestaion of a present thought with a present tense?
5. "He thought the Earth was round". He had this though. Such was his thought. But know he is long dead and so are his thoughts, so how dare we to use a present tense to tell about things long gone?