inventing falsehoods is easy, and therefore they are easy to vary once found; discovering good explanations is hard, but the harder they are to find, the harder they are to vary once found. The ideal that explanatory science strives for is nicely described by the quotation from Wheeler with which I began this chapter: ‘Behind it all is surely an id

I have often thought that the nature of science would be better understood if we called theories ‘misconceptions’ from the outset, instead of only after we have discovered their successors.

real cause would have been that one idea in the mind of that one hunter.

There is a saying that an ounce of prevention equals a pound of cure. But that is only when one knows what to prevent.

optimism is also a stance towards the future, because nearly all failures, and nearly all successes, are yet to come.

The hypothetical genes that caused meme replication by imitation would also have to specify whom to imitate.

(The idea that similar laws of physics can be expected to give rise to similar environments is undermined by the very existence of fine-tuning.)

Hence the frequently cited metaphor of the history of life on Earth, in which human civilization occupies only the final ‘second’ of the ‘day’ during which life has so far existed, is misleading. In reality, a substantial proportion of all evolution on our planet to date has occurred in human brains. And it has barely begun. The whole of biological

why the scientists are trying to learn the theory, and also why they have such disregard for faithfulness to the original, is that they want to know how the world is. Crucially, this is the same objective that the originator of the theory had. If it is a good theory – if it is a superb theory, as the fundamental theories of physics nowadays are – t