Lack of empathy for what we'll become

In the face of our universal inadequacy [...] man must go steeply up or down and the odds seem to be all in favor of his going down and out. If he goes up, then so great is the adaptation demanded of him that he must cease to be a man. Ordinary man is at the end of his tether.

(H. G. Wells: Mind at the end of its tether.)

Some folks might argue that it would be worth sacrificing all that makes us human if in exchange we were to receive the eternal life that's held out here. But if we aren't going to be the ones to receive this life, if instead it's going to beings that are not human and who won't use that life in pursuit of the things that make us human, then what stake do we have in such a future? Does it make any sense for us to root against our own species? I'm glad my computer has a large memory bank and a couple of the programs are fairly neat, but I'm not willing to exchange my life for them. Why would someone hope for the day when we exchange all of humankind for nothing more than such computer memory and programs? There's just something creepy and antihuman about this kind of desire and it makes Mr. Egan's imagined future seem awfully cold and uninviting. This is a future worth fighting against, though it's mildly diverting for a few hundred pages.

(from this review of Greg Egan's Diaspora in Brothers Judd)

Imagine a world where, by some natural and ineluctable process, each generation is slightly different - physically, mentally, and culturally - from the preceding one, but not so much that the preceding generation can't relate to it.

However, there's a number of generations N at which the accumulated changes would make it impossible for generation x to feel any kind of empathy towards generation x + N. In fact, they may even regard the people at x + N as abominations. Of course, when generation x + N comes along, all the people in generation x have long been dead.

But still, they might be aware of the historical trend. Suppose it takes one thousand years for N generations to come and go. Members of generation x will we looking at the complete extinction of their world - or at least, of anything they hold valuable and relatable in themselves - in 1000 years. How they would cope with that knowledge? If they really hate what they'll become, they could even set some kind of doomsday device to be activated a millenium in the future...

On a more down-to-earth note, which reformers and revolutionaries would still pursue their programs for change, if given complete knowledge of the effects of their reforms across time?