Circle of a sphere the Equator the only great circle. By contrast, all meridians of longitude, paired with their opposite meridian in the other hemisphere, form great circles. The diameter of the sphere which passes through the center of the circle is called its axis and the endpoints of this diameter are called its poles. A circle of a sphere can also be defined as the set of points at a given angular distance from a given pole. When the intersection of a sphere and a plane is not empty or a single point, it is a circle. This can be seen as follows:
What Is to Be Done? to become Marxists. He goes on to argue that to understand politics you must understand all of society, not just workers and their economic struggles with their employers. To become political and to become Marxists, workers need to learn about all of society, not just their own corner of it: Class political consciousness can be brought to the workers "only from without"; that is, only from outside the economic struggle, from outside the sphere of relations between workers and employers. The sphere from which alone it is possible to obtain this knowledge is the sphere of relationships (of "all" classes