I feel I may turn into a Wonga-Wonga bird imminently but I am not sure that there is an absolute clean slate because it disregards nature and leaves everything to nurture and we are slaves to our genes as much as our environment - I mean you are never going to teach a cow to sing even if you play it Mozart in utero and send it to Julliard...... Of course to an extent good and evil are socially defined concepts ... I think genes are important and they are selfish ...... there is usually an ulterior motive to social behaviour..... all in all we take as much as we can get away with ..... So in a way maybe we are born "evil" and trained (or not) to be good.....