I chose a random name from that list: Immanuel Kant. We went to the school's small library, and I searched and found the one book by Kant in the library: The Critique of Pure Reason. I quickly scanned through the book to see what I can find out about this Kant fellow, to be greeted with sentences such as:
> For how is it possible that the faculty of cognition should be awakened into exercise otherwise than by means of objects which affect our senses, and partly of themselves produce representations, partly rouse our powers of understanding into activity, to compare to connect, or to separate these, and so to convert the raw material of our sensuous impressions into a knowledge of objects, which is called experience?
and
> Whatever may be the content of our cognition, and in whatever manner our cognition may be related to its object, the universal, although only negative conditions of all our judgements is that they do not contradict themselves; otherwise these judgements are in themselves (even without respect to the object) nothing.
https://www.gutenberg.org/files/4280/4280-h/4280-h.htm
I remember closing the book, thinking to myself, "I can't write an essay about this guy", and finding it funny that his name was "I. Kant". I don't remember what I actually ended up doing for that essay. The deadline was very short so there was no possibility of reading a whole book, let alone that book (which anyways wasn't a great reference for writing about Kant, the person).
As an adult, I still find Kant's serpentine sentences incredibly difficult to digest. (Though some of the problems may originate from the translation.) Maybe I'm just a rube, but I wouldn't consider a sixth grader to have average intelligence if they read some Kant and come up with that criticism.
Update while writing this post: I'm not well versed in philosophy, so I quickly perused the Wikipedia summaries for Deontology and Consequentialism. The criticism, "The fatal flaw, as I understand it, in Kant’s deontological ethical system is his disregard of consequentialism." is rather shallow, wrapped in juicy terminology from moral philosophy. Though, I still think it's a notable feat for a sixth grader to read and even somewhat comprehend Kant.