This is exactly the sort of post that this blog was intended to promote:
As Raymond Williams points out in his excellent little book Keywords, from which I got the idea for this series, reform originally meant ‘restore the original form’ of something. In particular the Reformation was supposed to sweep away the abuses of the Papacy and restore the church to its original purity. As this example indicates, the worldview associated with this usage was one of decline rather than progress. The best one could hope for was to get back to things as they were in the good old days. This view was dominant in Western thinking from Plato to the 17th century.
From the 18th century onwards, reform underwent something of a reversal, since it now typically implied forming something new. But since the associated worldview was now one of progress, the assumption remained that reform entailed change for the better.
From the 18th century to the 1970s, the term reform was typically used to describe policies favored by the moderate left, in opposition to advocates of revolutionary change on one side and of conservatism and reaction on the other. From the 1970s to the end of the 20th century, though, the direction of policy change was reversed, with the rise of neoliberalism. However, the term reform continued to be used, even when the policies it described consisted of the dismantling of earlier reforms.