I will now take it that Adams and Aizawa ought to concede that there is no difference in content between my thought that ‘the harbour Bridge looks beautiful in the sunlight this morning’ and my utterance to you that ‘the Harbour Bridge looks beautiful in the sunlight this morning.’ Indeed I might think that very sentence to myself in my head before uttering it to you. If Adams and Aizawa are happy to accept this conclusion, then we really have no disagreement, because we have an example of thinking in natural language (English in this instance). Similarly it seems obvious to me that a Venn diagram that I am imagining now has the same meaning as the Venn diagram that I am drawing on the page now.Menary seems to me not to respect the difference between having a thought that P and have an English sentence with the content that P in one's head. Sure, one can have a thought with the content that the harbour Bridge looks beautiful in the sunlight this morning, and one can even "think this in English", but that's not to admit that there is an English sentence in the head that has the content "that the harbour Bridge looks beautiful in the sunlight this morning".
So, I now think that maybe A&A indulged the Clark and Menary discussion of these cases a bit too much. Spending a lot of time explaining their view may have obscured our view, which I think is pretty simple.
1) All thought is in mentalese (a system of mental representation that differs from all natural languages) which gets its semantic content by way of satisfying conditions on non-derived representations.
2) Thinking in English is forming mentalese representations of English sentences; it is not a matter of having tokens of English sentences in the head.
3) Thinking in images is forming mentalese representations of pictures; it is not a matter of having tokens of pictures in the head.
These are just statements of our view. There is a huge literature on mental imagery and a large literature on thinking in a natural language, so I would think it would take a lot of work on Menary's part to show that we are wrong on any of 1)-3). And, he is trying to show, or maybe is just assuming, that we are wrong on 1)-3).