The Watchmaker: my fav argument

[polymath257]

So how would you, for example, keep Lamarckism alive with revisions?

I'm not sure. I suppose you could shrink or shift it's scope and application. Gould apperantly viewed social learning as a form of Lamarckism. So we could change the theories focus from information that is inherited reproductively, to information that is inherited behaviorally.

Ptolomy's epicycles are a better illustration here. The insertion of epicycles was a revision made to geocentrism that brought it into harmony with observation, while maintaining it's central framework alive. I don't know what the epicycles of Lamarckism could be.

But the epicycles of Ptolemy did NOT keep it in harmony with observation. That is part of the point. Simply adding epicycles simply wasn't enough to get precise agreement with observations.

The Ptolemaic system was recognized as having problems during the middle ages. As more and more precise observations were made, the discrepancies between the Ptolemaic system and those observations became more and more clear. By the time Tycho was doing his observations, the only way to fix the problems were by throwing out the whole system and replacing it with heliocentrism. That Kepler was able to describe simple laws for the observed motion went a long way to killing the Ptolemaic worldview.

In addition to the positions, the Ptolemaic system was unable to explain the differences in brightness of the planets and how they changed over time.

When Galileo  discovered the phases of Venus and the moons of Jupiter, the Ptolemaic theory was dead. The basic scheme of the system was shown to be broken.

Then Newton came along and gave a *much* more accurate system, whereby the adjustments made depended on the actual masses of the planets. This was in contrast to the Ptolemaic system where the epicycles were introduced to 'preserve the appearances' with no actual theoretical motivation.

So, no, it *isn't* always possible to simply tweak a theory and keep it going. There are some observations that strike at the central assumptions of a model and show that model to be incorrect.