In a book there is the following sentence : "Since Plato, the more ambitious philosophers of education have often posed this question directly along with related questions concerning what is knowledge, reason, and truth."
My doubt is whether "what is knowledge, reason, and truth." an indirect question is. It seems to me that it is not, for every indirect question ought to put the verb after the subject. So I am guessing that it may be a sort of direct question, without a question mark though. Can anyone please help?