...ideas of things

Question

Therefore, if we could say of past philosophy that it has been an attempt to understand the world and man's place and destiny in it—an attempt necessarily conditioned by the class outlook, prejudices and illusions of the various exploiting class philosophers—we have to say of Marxist philosophy that it is an attempt to understand the world in order to change the world and to shape and realise man's destiny in it. Dialectical materialism is a theoretical instrument in the hands of the people for use in changing the world. Marxism, therefore, seeks to base our ideas of things on nothing but the actual investigation of them, arising from and tested by experience and practice. It does not invent a "system" as previous philosophies have done, and then try to make everything fit into it.

from Materialism and the Dialectical Method - Maurice Cornforth

In the context, what did the author mean by "them"? "ideas of things" or just "things"?

Answer 1

"Ideas of things" is a broad way of saying "theories or philosophies," i.e. about the world.

The sentence is claiming that Marxism is a form of empiricism, basing its theories on observations about the world and human society and behavior ("ideas of things") solely on real observations of the "things themselves." The author is contrasting this scientific and unbiased approach to philosophy and politics, with the earlier capitalist or aristocratic views, which the author I'm sure would claim are based on a priori ideas of Divine Right, religious norms, or other class-based assumptions. The latter not being grounded in reality, but on what the aristocrats wish to be true, to maintain their place on top of society.

Whether this is an accurate description of Marxism is another question entirely, outside the scope of this forum.