Imagine that tommorow you are told from now you will rule the world. How will you rule, who will you appoint to be your trusted members to assist you in your rule? Well it will probably be individuals who have common ideas and similar goals like you, and based on that the world would be ruled in a unique and specific way. Marx stated that the ideas of the ruling class(you) will be the ruling ideas which will define society, and what society may see as good or bad.
I agree with him. For example, When our founding fathers created the constitution, they created it based on their perspective on how things should be. However, the majority of them were from a similar intellectual background; they were the ruling class and their ideas determined how the rest of society would be dealt with. The ruling class was composed of human beings, and these individuals naturally have personal goals and certain backgrounds which determine their perspective on things.
Therefore, this can be very negative because in reality how do we know if our government is really out there to look for us? Is the media used in a particular way to hide the true ideas and intentions of the ruling class?? Their ideas do determine the ruling ideas; therefore, neither you or I may never know the absolute truth of many things which may feel like common society could resemble puppets and the ruling class, their masters.