I found it difficult this morning to get my brain moving!
One of recurring themes that appears in any discussion on the concept of progress (the comments on Winton's Could civilization be maintained without progress? are a current example) is the relationship between progress and economic development where economic development is often interpreted as increases in per capita income.
Another view of progress that Neil Whitfield pointed me to is The Idea of Progress by J. B. Bury (1920). I haven't read this book; another gap in my reading! The preface to Bury's book says in part:
Under the control of the idea of Progress the ethical code recognised in the Western world has been reformed in modern times by a new principle of far-reaching importance which has emanated from that idea. When Isocrates formulated the rule of life, "Do unto others," he probably did not mean to include among "others" slaves or savages. The Stoics and the Christians extended its application to the whole of living humanity. But in late years the rule has received a vastly greater extension by the inclusion of the unborn generations of the future. This principle of duty to posterity is a direct corollary of the idea of Progress. In the recent war that idea, involving the moral obligation of making sacrifices for the sake of future ages, was constantly appealed to; just as in the Crusades, the most characteristic wars of our medieval ancestors, the idea of human destinies then in the ascendant lured thousands to hardship and death.
Ideas are slippery things. They exert great power, but you constantly need to define and refine to ensure that you have a common base for discussion. This is especially true for embedded ideas, those simply accepted as part of a given way of thinking.
In discussion on the ideas of civilisation and progress, a friend at work vehemently denied that there had been progress. To her mind, the growth in the human population and the pressures this had placed on the earth were, of themselves, sufficient to invalidate the very idea that there had been progress.
The dedication to Bury's book reads:
Dedicated to the memories of Charles Francois Castel de Saint-Pierre,
Marie Jean Antoine Nicolas Caritat de Condorcet, Auguste Comte, Herbert
Spencer, and other optimists mentioned in this volume.
Optimists: now there's a word that I can identify with. You can be a pessimist and still believe in the concept of progress, if only as something that hasn't happened or cannot be achieved! Yet to believe that real change is possible, that there has been advancement, that further advancement is possible. I think that requires a degree of optimism.
I will have to leave things there to get ready for the day.