Good for you. Consider telling him that becoming pessimistic is a perfectly natural and completely understandable response to the pain he's been witnessing and experiencing and that you understand this.
Also plant the seed that a pessimist is one who often doesn't enjoy life or do "what's right, what's best or what's fun', because of X, while an optimist enjoys life and will do them despite X.
Ask him which he thinks is the stronger stance.
And with the PMA: You're the Dad. You've got to lead on this, model this. Hell, fake it for now, just so long as they see it in you and are able to take their cue from you.
Gardener
"My soul, be satisfied with flowers, With fruit, with weeds even; but gather them In the one garden you may call your own." Cyrano deBergerac
