Is it even possible, happiness? According to Leszek Kołakowski, it isn't. It isn't possible for God and it isn't possible for us. I'll confine myself to the case of us - human beings. The crux of Kołakowski's argument is that we can't overlook 'the existence of evil and the misery of the human condition'; we can't 'eliminate the anticipation of death or the sorrows of life'. Some may believe they are happy but that is merely self-deception.
I wouldn't lightly set aside his argument. In the face both of the types of enormity I've just posted about and the ordinary griefs and frailties of human existence, it is hard to quarrel with the tendency of these reflections. However, I note that in posing the central question, Kołakowski writes:
But is it possible to be aware of evil and suffering and still be perfectly happy?
And he says, too, that 'happiness as an immutable condition is not accessible to us'. Doesn't the notion of perfect and immutable happiness skew the issue? In If This Is A Man Primo Levi writes that 'Sooner or later in life everyone discovers that perfect happiness is unrealizable...'; this he observes not specifically in connection with Auschwitz but as a general truth - which it is.
So there's another question here: that of whether happiness in a more limited sense than perfect happiness is possible. I don't believe it is something that should be given up on, either personally or politically.