it was only with the advent of Newton’s theories about the behaviour of invisible entities such as forces and momentum that they began to understand what was needed in order to go there.
This increasingly intimate connection between explaining the world and controlling it is no accident, but is part of the deep structure of the world. Consider the set of all conceivable transformations of physical objects. Some of those (like faster-than-light communication) never happen because they are forbidden by laws of nature; some (like the formation of stars out of primordial hydrogen) happen spontaneously; and some (such as converting air and water into trees, or converting raw materials into a radio telescope) are possible, but happen only when the requisite knowledge is present – for instance, embodied in genes or brains. But those are the only possibilities. That is to say, every putative physical transformation, to be performed in a given time with given resources or under any other conditions, is either
– impossible because it is forbidden by the laws of nature; or
– achievable, given the right knowledge.
That momentous dichotomy exists because if there were transformations that technology could never achieve regardless of what knowledge was brought to bear, then this fact would itself be a testable regularity in nature. But all regularities in nature have explanations, so the explanation of that regularity would itself be a law of nature, or a consequence of one. And so, again, everything that is not forbidden by laws of nature is achievable, given the right knowledge.
This fundamental connection between explanatory knowledge and technology is why the Haldane–Dawkins queerer-than-we-can-suppose argument is mistaken – why the reach of human adaptations does have a different character from that of all the other adaptations in the biosphere. The ability to create and use explanatory knowledge gives people a power to transform nature which is ultimately not limited by parochial factors, as all other adaptations are, but only by universal laws. This is the cosmic significance of explanatory knowledge – and hence of people, whom I shall henceforward define as entities that can create explanatory knowledge.
For every other species on Earth, we can determine its reach simply by making a list of all the resources and environmental conditions on which its adaptations depend. In principle one could determine those from a study of its DNA molecules – because that is where all its genetic information is encoded (in the form of sequences of small constituent molecules called ‘bases’). As Dawkins has pointed out:
A gene pool is carved and whittled through generations of ancestral natural selection to fit [a particular] environment. In theory a knowledgeable zoologist, presented with the complete transcript of a genome [the set of all the genes of an organism], should be able to reconstruct the environmental circumstances that did the carving. In this sense the DNA is a coded description of ancestral environments.
In Art Wolfe, The Living Wild, ed. Michelle A. Gilders (2000)
To be precise, the ‘knowledgeable zoologist’ would be able to reconstruct only those aspects of the organism’s ancestral environment that exerted selection pressure – such as the types of prey that existed there, what behaviours would catch them, what chemicals would digest them and so on. Those are all regularities in the environment. A genome contains coded descriptions of them, and hence implicitly specifies the environments in which the organism can survive. For example, all primates require vitamin C. Without it, they fall ill and die of the disease scurvy, but their genes do not contain the knowledge of how to synthesize it. So, whenever any non-human primate is in an environment that does not supply vitamin C for an extended period, it dies. Any account that overlooks this fact will overestimate the reach of those species. Humans are primates, yet their reach has nothing to do with which environments supply vitamin C. Humans can create and apply new knowledge of how to cause it to be synthesized from a wide range of raw materials, by agriculture or in chemical factories. And, just as essentially, humans can discover for themselves that, in most environments, they need to do that in order to survive.
Similarly, whether humans could live entirely outside the biosphere – say, on the moon – does not depend on the quirks of human biochemistry. Just as humans currently cause over a tonne of vitamin C to appear in Oxfordshire every week (from their farms and factories), so they could do the same on the moon – and the same goes for