There exists a widespread misconception that when we are to judge the moral merits of some ideology the nuanced and proper way to do this is to line up the "good stuff" on one side and the "bad stuff" on the other, and then sort of add them together and pronounce the "sum" to be the moral value of the ideology as such. In this view, then, a "good idea" may cancel out a "bad idea", or even overshoot it, so that the net result is "good". Related to this, in particular in reference to religionist ideologies, is the "defence" that we cannot judge the whole magnificent vision merely on basis of one element of it that we may find objectionable; we are obliged to consider (and not the least know about!) the "whole" vision in order to judge it properly (leaving, accidentally, only theologians as the only ones truly capable of assessing the value of their particular creed..) But, in my view, this conception of a moral "arithmetic" is deeply flawed. Suppose we found the fragments of an ancient "Ethics regulations book" that seems to have had at least 10.000 regulations, but the only ones legible are these: "245. If you see a child in pain and distress, try to comfort it, even if it is not your own child 1258. It is worthy of you, if you have a shilling to spare, to give it to someone in need of it. 5679. On fridays, roast a baby in your oven 10003. If a stranger is lost, and ask of you directions, tell him so gladly, without distortion" Now, do we really need to know all the rest of these regulations before we may condemn it as vile, on account of regulation 5679? Not at all! Furthermore, would the system, as a whole, improve much if all the rest of the regulations were like 245 or 10003? That idea is simply absurd; every subset ideology of these regulations that contain 5679 is as morally bad as the single subset containing ONLY 5679! Only those ideology subsets that do NOT include 5679 might be regarded as moral; 5679 contaminates, by its vileness, every subset it belongs to. Thus, a more proper rule of thumb for judging the moral merits of ideologies is the following: "An ideology is at least as bad as its worst contained element"