From Serendipity to Justification
Clearly, then, a dynamic science makes certain things possible that otherwise would be not only beyond our reach but also beyond our imagination. That is one of the main reasons why we cannot afford not to do science: many problems of which we are already aware cannot be solved unless a different point of view comes into play. Therefore to reject or slow down the process by which science grows, by which we refine and replace our communal spectacles, amounts to a decision to deprive ourselves of much that is good and to continue to expose ourselves unnecessarily to who knows what dangers.
Supporters of space exploration can now justify their expectation of a bounty from space precisely because exploration presents many challenges to our science and technology. Since space exploration is thus so likely to contribute to the transformation of our views, investing in it has a clear advantage over investing in fields not so ripe with challenge.
Knowing that serendipity is a natural consequence of science, the supporter of exploration may now say with Descartes that a failure to explore is a failure to carry out our obligation to "procure the general good of mankind." The justification the supporter can now offer for exploration in general, and for the heart of space exploration in particular, sounds like a practical case, albeit more subtle and indirect than the one made in Chapter 2. But it is a practical case born out of the nature of space science itself, and thus the guarantees that it offers go well beyond those of historical anecdotes.
This deeper and fundamental practicality forms the basis of the supporter's response to the strongest social objections. The supporter of exploration can now explain to the social critic why the previous benefits of exploration were not a fortunate accident: they were the result of the inevitable expansion of opportunity that is part and parcel of scientific exploration. Once we understand the dynamic nature of science we are in a position to vouch for its future serendipity. As we saw in the previous chapter, to a casual observer the heart of space exploration may not appear to have obvious practical benefits. But this deeper investigation reveals a long-term, fundamental practicality: the practicality that comes when a transformation of our views of the universe expands our range of opportunity.
As the benefits from exploration become routine, the frontier of the unknown is pushed further out into the cosmos and our challenges shift accordingly. In indulging our enthusiasm, we are thus bound to force a change in our panorama of problems and opportunities.
The argument works against the ideological objection as well. Unless we commit species suicide, we will continue to interact with the Earth and transform it in small and large ways. By doing so we act in the manner of all other living beings: a tree grows tall and gives shade to violets and mushrooms that could not have lived without it; a beaver builds a dam, harming rose bushes and fish, but helping water lilies and frogs; and once upon a time, bacteria gave the Earth its oxygen and nitrogen atmosphere.
The question for us is not whether we will interfere, but rather how much and how wisely. Now, to act wisely we need knowledge of ourselves, of the Earth, and of our interactions with the Earth. Otherwise we are likely to impose too big a burden on the planet or on its human inhabitants.
Such knowledge is not complete as of this writing – not even environmental activists can reasonably claim that they know everything about our planet – and it may never be complete. That is, our perspective is limited, and therefore we need a dynamic science that can change our panorama of problems and opportunities. To eschew dynamic science is to deprive humankind of the chance to act wisely. We are already a big presence on the Earth and need to move carefully in the dark of our ignorance. It would thus be irresponsible to forgo the lanterns that may illuminate our way (lanterns such as NASA’s Mission to Earth, to be discussed in the next chapter). Space exploration is thus not a false panacea but an important means to a cleaner and better future.
 We may also expose ourselves to new risks. I will discuss this matter in the last two chapters.
 Cf. the remarks made at the end of Ch. 2 about those aspects of exploration that fire the imagination and motivate the conquest of the cosmos.
. Historians may point out that the argument sketched in the two previous sections of this chapter is largely based on history and so they may wonder about my remarks in Chapter 2 against a historical case for serendipity. The answer is that here I place the history of science in a philosophical context. Several of my premises do require the history of science for their support, but my conclusions are not the results of inductive inferences from history. They depend instead on conceptual inferences about the nature of science and exploration. This is what makes my argument philosophical.