> We learned to think by writing only after writing became cheap. Yes, we’ve trained our brains to develop ideas by editing raw thoughts on paper, but it is just one of the possible methods.

I think you have some misconceptions here. First, the article does not claim that thinking is writing, and especially not that there is no thinking without writing. They only explain that writing is supporting and driving a higher quality of thinking.

Second, paper isn't the only medium to write. And writing isn't the only persistent form of communication to support and improve thinking.

> Thinking used to be detached from writing.

It still is.