He has also said that saying something in a specific frame of mind is thinking a thought. 

1. said 后面是that 宾语从句。

2. 在宾语从句中，含有两个动名词短语，分别作主语和表语：

saying something in a specific frame of mind （主语）is （系动词）thinking a thought（表语）. 

3. think a thought：thought 是think 的同源宾语。“思考一个想法”。

【翻译】他还说过，在特定的心境下说某件事就是在思考一个想法。