Ideas can only advance if they are persuasive, but this aspect frequently gets left off of accounts of the history of ideas. We can easily talk about the advance of ideas as though they propagated by microbes – as though subjectivism, nominalism, nihilism, etc. were all transmitted by coughing or rats or a failure to wash our hands. In fact they were propagated because a great number of people found them convincing, or found some other reason to believe them.
Ideas aren’t believed by everyone for the same reason, and historians can’t be asked to read minds, but there should be more of an effort to figure out exactly what was so convincing in those ideas we see as catching on, especially when they define whole eras or movements.