This is a post by Valentine Simpson (University of Valencia).

You would be blameless for believing that a thought is a shareable thing. Indeed, it seems that subjects do a lot of thinking together, that they regularly exchange thoughts in communicating with each other, and that much (if not all) of what we accomplish as a society owes to our ability to pass information on to one another, in the form of my getting you to think that which I also think. Plausibly, this capacity is underpinned by our further sharing of a public language, with words and meanings that are also common to all.