I know that you thought that this was a funny question, but the answer is partly yes and partly no. I know this because I used to be a practicing psychic. I could only relay as much as I knew how to translate, and that was limited by my experience.<br />
As an example, if Nostradamus really did see things that seem to describe tanks and bombers, but his experience did not include knowledge of the internal combustion engine or atomic bombs, it's impossible to find words that haven't been invented yet and then translate them into words that the client (psychic or not) can understand.
I love this question.