For me, scientific knowledge is divided into mathematical sciences, natural sciences dealing with the natural world (physical and biological), and sciences dealing with mankind (psychology, sociology, all the sciences of culture achievements, and every kind of historical knowledge). Apart from these sciences is philosophy, about which we will talk later. In the first place, all this is pure or theoretical knowledge, sought only for the purpose of understanding, in order to fulfill the need to understand what is intrinsic and consubstantial to man. What distinguishes man from animal is that he knows and needs to know. If man did not know that the world existed, and that the world was of a certain kind, that he was of a certain kind, he wouldn’t be man. The technical aspects or applications of knowledge are equally necessary for man and are of the greatest importance, because they also contribute to defining him as man and permit him to pursue a life increasingly more truly human.
But even while enjoying the results of technical progress, he must defend the primacy and autonomy of pure knowledge. Knowledge sought directly for its practical applications will have immediate and foreseeable success, but not the kind of important result whose revolutionary scope is in large part unforeseen, except by the imagination of the Utopians. Let me recall a well-known example. If the Greek mathematicians had not applied themselves to investigation of conic sections, zealously and without the least suspicion that it might someday be useful, it would not have been possible centuries later to navigate far from shore. The first men to study the nature of electricity could not imagine that their experiments, carried on because of mere intellectual curiosity, would eventually lead to modern electrical technology, without which we can scarcely conceive of contemporary life. Pure knowledge is valuable for its own sake, because the human spirit cannot resign itself to ignorance. But, in addition, it is the foundation for practical results that would not have been reached if this knowledge had been sought disinterestedly.
The practical scientist ______.

As a result, biologists, evolutionary anthropologists, sociologists and demographers are starting to pay more attention to grandmothers: what they did in the past, whether and how they made a difference to their families’ welfare, and what they are up to now in a sampling of cultures around the world.At a recent international conference —the first devoted to grandmothers —researchers concluded with something approaching a consensus that grandmothers in particular, and elder female kin in general, have been an underrated source of power and sway in our evolutionary heritage. Grandmothers, they said, are in a distinctive evolutionary category. They are no longer reproductively active themselves, as older males may struggle to be, but they often have many hale years ahead of them; and as the existence of substantial proportions of older adults among even the most "primitive" cultures indicates, such durability is nothing new.
If, over the span of human evolution, postmenopausal women have not been using their Stalwart bodies for bearing babies, they very likely have been directing their considerable energies elsewhere.
Say, over the river and through the woods. It turns out that there is a reason children are perpetually yearning for the flourdusted, mythical figure called grandma or granny or oma or abuelita. As a number of participants at the conference demonstrated, the presence or absence of a grandmother often spelled the difference in traditional subsistence cultures between life or death for the grandchildren. In fact, having a grandmother around sometimes improved a child’s prospects to a far greater extent than did the presence of a father.
Dr. Ruth Mace and Dr. Rebecca Sear of the department of anthropology at University College in London, for example, analyzed demographic information from rural Gambia that was collected from 1950 to 1974, when child mortality rates in the area were so high that even minor discrepancies in care could be all too readily tallied. The anthropologists found that for Gambian toddlers, weaned from the protective balm of breast milk but not yet possessing strength and immune vigor of their own, the presence of a grandmother cut their chances of dying in half.
"The surprising result to us was that if the father was alive or dead didn’t matter," Dr. Mace said in a telephone interview. "If the grandmother dies, you notice it; if the father does, you don’t."
Importantly, this beneficent granny effect derived only from maternal grandmothers —the mother of one’s mother. The paternal grandmothers made no difference to a child’s outcome.

A. the young are less tolerant of discomforts in life
B. the divorce rate in Japan exceeds that in the U.S.
C. the Japanese endure more than ever before
D. the Japanese appreciate their present life