Now one could say, at the risk of some superficiality, that there exist principally two types of scientists. The ones, and they are rare, wish to understand the world, to know nature; the others, far more frequent, wish to explain it. The first are searching for truth, often with knowledge that they will not attain it; the second strive for plausibility, for the achievement of an intellectually consistent, and hence successful, view of the world.