<?php
class Attributes {
	static $honesty = 1;
}

class Person {
	private $attributes;
	public function getAttr($attr) {
		if(isset($this->attributes[$attr])) {
			return $this->attributes[$attr];
		} else {
			return null;
		}
	}
	public function setAttr($attr, $value) {
		$this->attributes[$attr] = $value;
	}
}

class WhiteWolf extends Person {
	public function __construct() {
		$this->setAttr(Attributes::$honesty, 10); //some arbitrary value
	}
}

$ww = new WhiteWolf;
$ww->setAttr(Attributes::$honesty, $ww->getAttr(Attributes::$honesty) - 1);