A public declaration, usually of a prince, sovereign, or other person claiming large powers, showing his intentions, or proclaiming his opinions and motives in reference to some act done or contemplated by him; as, a manifesto declaring the purpose of a prince to begin war, and explaining his motives.
A snappy label and a manifesto would have been two of the very last things on my own career want list. That label enabled mainstream science fiction to safely assimilate our dissident influence, such as it was. Cyberpunk could then be embraced and given prizes and patted on the head, and genre science fiction could continue unchanged. William Gibson
I didn't have a manifesto. I had some discontent. It seemed to me that midcentury mainstream American science fiction had often been triumphalist and militaristic, a sort of folk propaganda for American exceptionalism. William Gibson
It's much easier to wear a Chairman Mao button and shake your fists in the air and all that, then to actually read the Communist manifesto and things like that and actually become involved in politics. Lester Bangs