Excellent discourse (Pepys' diary entry of 2.4.1664)

At noon to the coffee-house, where excellent discourse with Sir

W. Petty; who proposed it, as a thing that is truly questionable,

whether there really be any difference between waking and dreaming --

that it is hard not only to tell how we know when we do a thing really

or in a dream, but also what the difference between one and the other.