That's a bit of trivialization into a tautology. Systems continue to exist, but most of them also change in various aspects - some superficial, some fundamenta

That's a bit of trivialization into a tautology. Systems continue to exist, but most of them also change in various aspects - some superficial, some fundamental. Republican Rome was quite different from what Imperial Rome ended up being; the US of the 1800s is very different from the US of today.