That is why Comte regarded the appearance of a sacerdotal class, specially occupied with speculative research, as a decisive moment in history of humanity. It matters little that these researches should have remained chimerical and absurd during long centuries. The essential point was that the human mind should form and keep the habit of disinterested speculation, that it should not rest content with immediately applicable knowledge, and that it should exert itself towards a theoretical conception of nature, however simple at first that conception was bound to be. Thus, science has, properly speaking, two roots, the one practical, the other theoretical. If it originated in the primitive arts, it is no less closely allied with primitive philosophy. It still bears features which enable us to discern this twofold filiation. On the one hand, it has remained _speculative_ as was the theological philosophy which first dominated over the human mind. Only this speculation has gradually abandoned everything except the laws of phenomena, and it has ended by undermining the theological conceptions from which it came. On the other hand, science has remained _real_, like the popular wisdom which gave it birth. But, while dealing with given phenomena in experience, it has developed in the direction of theory. Instead of only considering scenes of concrete objects, it has resolved them into their elements. A more and more powerful analysis has raised it to the consideration of laws more and more general and abstract. Thus, while the popular wisdom is limited to empirical generalisations, a science such as, for instance, astronomy discovers the law which governs the whole of an immense order of phenomena. From this general idea of science the following consequences at once follow: 1. Science is the collective work of humanity. It bears upon an object common to all: Reality. It employs the method common to all: the positive method. All intellects work in the same manner on a common ground. It is what Comte calls “the profound mental identity of learned men with the crowd whose destiny fulfils itself in active work.[31]” The progress of the scientific mind is a methodical extension of popular common sense to all subjects accessible to human reason. But here method does almost everything. “The whole superiority of the philosophical mind over the popular common sense results from a special and continuous application to common speculations, in starting prudently from the initial step, after having brought them back to a normal state of judicious abstraction, for the purpose of generalising and coordinating. For, what ordinary intellects chiefly lack, is less the precision and penetration appropriate for discerning partial approximations, than the aptitude for generalising abstract relations, and for establishing a perfect logical coherence among our various notions.”[32]