[But] perhaps this one is the ultimate paradox - the identification of the evanescent moment, the now, the ever-beginning, ever-perishing transience of the present with the ultimate reality which accounts for everything else, no matter how permanent or intricate, or noble, in the world. And yet this is certainly what Whitehead means to do.
Let there be no misunderstanding. Whitehead doesn't mean merely that through experience we "know" or have representations of the real world. Nor, at the other extreme, is he a solipsist. Experience is reality, but so is the world out there which is experienced.
... Things are so turbulent and wild - since actuality is nothing but an avalanche of fleeting moments of process - that the universe would fly apart in a millisecond if it were not for the unobtrusive, cohesive function of eternal objects.