We now have the fundamentals of ecologism in place. We have discussed its critique of contemporary society, we have outlined its proposals for an ecologically sound society, and we have assessed its approach to bringing such a society about. I have claimed that ecologism is a new political ideology, worthy of attention in the new millennium alongside other more familiar ones such as liberalism, conservatism and socialism. If this is correct, then it is only natural to want to compare and contrast this new ideology with those which it seeks to challenge. That is what I propose to do in this chapter. In so doing, it is my intention to deepen our understanding of what marks ecologism off from those other ideologies. I shall be arguing that attempts by liberals, conservatives and socialists to appropriate ecological thought for themselves will founder, since, as I pointed out in the Introduction, ecologism is as different from each of them as they are from each other. The examination carried out in this chapter should drive home this point.