From Ethical Politics
To be progressive is to believe that history moves in a direction of improvement. From the European Enlightenment onwards, this had usually meant that material conditions for all of humanity were assumed to be ameliorable, even if the actual movements of history were never actually quite so clear.
A particularly attractive and eloquent version of the ideal of progress is Gottfried Leibniz's at the end of his essay ‘On the Ultimate Origination of Things’ (1697):
… there is a perpetual and a most free progress of the whole universe towards a consummation of the universal beauty and perfection of the works of God, so that it is always advancing towards a greater development. Thus, even now a great part of our earth has received cultivation, and will receive it more and more. And though it is true that there are times when some parts of it go back again to virgin forest, or are destroyed again and oppressed, this must be understood in the same sense as I just now interpreted the meaning of affliction, namely, that this very destruction and oppression contributes to achieve something greater, so that in some way we receive profit from our very loss.
To the objection that may perhaps be offered that if this were so the world long ago would have become a paradise, the answer is at hand: although many substances have already come to great perfection, yet owing to the infinite divisibility of what is continuous, there always remain in the abyss of things parts that are asleep, and these need to be awakened and to be driven forward into something greater and better — in a word, to a better state of development. Hence this progress does not ever come to an end. (G. VII; Everyman, trans. Morris and Parkinson, p. 308.)
The idea of progress in history has been criticised by conservatives and "realists". But it has also come to be criticised by progressives themselves. So, for example, Michel Foucault sees as itself pathological the Enlightenment's need to discover a truth in history as tending towards some desirable end-point.
The ecological critique of progress is first a critique of the measure of progress as being material conditions. More is not better. However, a more radical critique, of the sort proposed by Michel Foucault, is also attractive to some ecological perspectives: the search for progress is in itself destructive.