Sorrow be damned & all your plans. Fuck the faithful, fuck the committed, the dedicated, the true believers; fuck all the sure & certain people prepared to maim & kill whoever got in their way; fuck every cause that ended in murder & a child crying.

Iain Banks (1954-2013) Scottish author
Against a Dark Background (1993)

Often paraphrased as "Fuck every cause that ends in murder and children crying."