No individual wrote the Constitution. It was a collective effort. Yet it has features of a work we would expect from a consciousness, such as a view of itself as embedded in a larger historical context. I don't have a hard time seeing that document as a form of speech emitted by a conscious collective. And not knowing exactly how human individual consciousness works, it isn't very clear whether such collective consciousness is a metaphor or an example. Especially when individual consciousness seems to emerge from a collective of neurons.