There is a version of morality which says that a bad outcome can be justified if a greater good is achieved or is at least the aim of the action. War is a typical case. We all accept that in an ideal world, we would not go around killing people. However, we will feel justified in going to war with an aggressor if the alternative is that our own lives or liberty are at risk. The greater good is the defence of my country against someone who quite unjustifiably wishes to harm us. Similar reasoning applies if someone breaks into my house: I am now encouraged to do anything short of the use of 'grossly disproportionate force' to defend my person and property. The good is the defence of what is mine against someone who unlawfully tries to take it from me. But quite obviously, such a way of thinking is highly subjective.

Perhaps we could look at another example. In the pursuit of its 'War on Terror', the coalition forces are using drones to attack individual members of Al Quaida and the Taleban. At least, that is the theory. For a long time now, we have been told that there were such things as smart armaments which could 'take out' the intended target without causing collateral damage. I first remember coming across this idea in connection with the first Gulf war. We were told that Cruise missiles had such a sophisticated guidance system that it could go up one street, turn right, turn left go through the front door of number 23 and only then explode. Of course, this was an ever so slight exaggeration as was discovered when the war was over. Now, it may be that the sat-nav used by drones is better than the version used in the Cruise missiles, but I wouldn't bet on it being much better than the ones we use and we all know what trouble they can get us into, with lorries ending up in narrow country lanes and having to be got out with cranes.

But that is not even the main point. As we know from countless reports of their use, they most certainly do inflict collateral damage. The drone blowing up an alleged terrorist in a small village will almost inevitably kill or injure others living there. Then there is the fact that identification of the supposed terrorist cannot be 100% accurate. Life doesn't work like that. There may be a high degree of confidence that this is indeed the person, but that confidence is not always warranted. So what is the justification? Well, it seems to be the 'Higher Good'. We have to get rid of these people in order to win the War on Terrorism and if we kill or injure some innocent people along the way, well that's sad but justifiable in trying to attain that higher good.

Which brings us on to Jimmy Saville. That icon of charity work, cheekiness and of fixing it for adoring children turns out, it seems, to have been a major, serial paedophile. That, at any rate, is the conclusion of the police and the NSPCC as I write. So far some 300 people have made complaints to the police about him and what he did to them.

Now, we can talk about a different culture in the 70's. We can say that the pop world has always attracted young girls wanting to be more than a little friendly with their heroes. But we need really to approach things from a different direction. Not only did he take advantage of his status amongst the groupies attending Top of The Pops, but he used his starry image to take advantage of kids in hospital who were not lining up outside his door, but feeling very ill and just wanting to get better. And we see that those in authority - nurses in wards and no doubt others - turned a blind eye to what was going on because of who he was. Journalists are said to have failed to investigate, when it was pointed out to them by Jimmy Saville himself (!) that it would bring to an end his charitable fund-raising potential, something which over the years has brought in some £40 million pounds.

No doubt in their own minds they would have persuaded themselves that his 'attentions' were perhaps not all that bad, that it was maybe just Jimmy being Jimmy. So we heard nothing of this until after his death, when his ability to raise money had ceased. Until then, the juggernaut of his charity-raising work stopped people from acting to protect the children for whom they were responsible and, here, I include the under-age groupies lined up outside his dressing room who should have been protected from their own lack of judgement. The argument was, evidently, that there was a greater good which came from indulging his activities. And all the time, he was deliberately using that charitable work to cloak his real desires, to hide them from an admiring public.

Which brings us back to war and drones. The reason we think that the good we are trying to achieve outweighs the horror of what we are doing is often the result of a failure to see things as they are. Just as those looking at Jimmy Saville may have been able to persuade themselves that things were not as bad as they were, so those who justify killing will engage in a form of wilful blindness. After all, we do not know the people who are killed, so it is relatively easy not to feel empathy for them, particularly if they live in a country with a very different way of life. And if they were 'with' the terrorist, then they must have shared his views surely? So we ignore the fact that terrorists live amongst people who often have no desire to be involved, but have no choice but to be there. They cannot just move to another place. I think that the test is whether we would think the same if the drones were landing in England. And for war in general, it is almost invariably the case that it is accompanied by propaganda to vilify the people of the nation with whom we are at war. Our leaders know that we need to see them as less than human in order to remove the empathetic link which we might otherwise have.

So then what conclusion can we draw from all this? I am not arguing that the greater good argument is never valid. For instance, without it we would never get any roads built or any other infrastructure put in. From the days of the inauguration of the canal system up to HS2, the idea of compulsory acquisition of people's land to make way for our national infrastructure has been a necessary part of our progress. However, very few people would want the compensation on offer if they could instead be left in peace where they are. Hence the rise and rise of the Nimby. But, as a nation, we need these infrastructure works and so the greater good demands that those who are in the way are disadvantaged, even if we sweeten the pill by paying them their removal expenses and an amount equal to the market value of what we have taken.

No, the principle of the greater good is one we all sign up to. The problem lies in how to be sure that the greater good really is a greater good and not just us being lazy in our thinking or simply deluding ourselves.