Socialism is a science. But it is not like botany, or electronics, or chemistry. Students who really want to understand Marxism won't sell themselves short by going to secondary sources. They will go to original sources. They will go to the works of Karl Marx and Frederick Engels, the founders of scientific socialism, to Daniel De Leon and to the works of other recognized exponents of Marxism.
Socialism is a science of considerable dimensions.
It involves history, sociology, politics, economics and even anthropology. A study of socialism leads into all these fields. But all aspects of socialism dovetail, and scientific socialism may be said to rest on three basic theories or principles. The law of value, with its corollary theory of surplus value. The class struggle.