I’m scared to read it but I found the original essay that I referenced in #mydaddyissueswithdavidfosterwallace. This is what he would say to his students—

I don’t know whether anybody’s told you this or not,
but when you’re in a college English class you’re basically
studying a foreign dialect. This dialect is called ‘Standard
Written English. … From talking with you and reading
your essays, I’ve concluded that your own primary dialect
is [one of three variants of SBE common to our region]. Now,
let me spell something out in my official Teacher-voice:
The SBE you’re fluent in is different from SWE in all kinds
of important ways. Some of these differences are
grammatical — for example, double negatives are OK
in Standard Black English but not in SWE, and SBE
and SWE conjugate certain verbs in totally different
ways. Other differences have more to do with style —
for instance, Standard Written English tends to use a lot
more subordinate clauses in the early parts of sentences,
and it sets off most of these early subordinates with commas,
and, under SWE rules, writing that doesn’t do this is “choppy.”
There are tons of differences like that. How much of this
stuff do you already know?
[STANDARD RESPONSE: some variation on “I know from
the grades and comments on my papers that English profs
don’t think I’m a good writer.”]
Well, I’ve got good news and bad news. There are some
otherwise smart English profs who aren’t very aware that
there are real dialects of English other than SWE, so when
they’re reading your papers they’ll put, like, “Incorrect
conjugation” or “Comma needed” instead of “SWE
conjugates this verb differently” or “SWE calls for a comma
here.” That’s the good news — it’s not that you’re a
bad writer, it’s that you haven’t learned the special
rules of the dialect they want you to write in. Maybe
that’s not such good news, that they were grading you
down for mistakes in a foreign language you didn’t even
know was a foreign language. That they won’t let you write
in SBE. Maybe it seems unfair. If it does, you’re not going
to like this news: I’m not going to let you write in SBE
either. In my class, you have to learn and write in SWE.
If you want to study your own dialect and its rules and history
and how it’s different from SWE, fine — there are some
great books by scholars of Black English, and I’ll help you
find some and talk about them with you if you want. But
that will be outside class. In class — in my English class —
you will have to master and write in Standard Written English,
which we might just as well call “Standard White English,”
because it was developed by white people and is used
by white people, especially educated, powerful white people.
[RESPONSES by this point vary too widely to standardize.]
I’m respecting you enough here to give you what I believe is the straight truth. In this country, SWE  is perceived as the dialect of education and intelligence and power and prestige, and anybody of any race, ethnicity, religion, or gender who wants to succeed in American culture has got to be able to use SWE. This is How It Is. You can be glad about it or sad about it or deeply pissed off. You can believe it’s racist and unjust and decide right here and now to spend every waking minute of your adult life arguing against it, and maybe you should, but I’ll tell you something: If you ever want those arguments to get listened to and taken seriously, you’re going to have to communicate them in SWE, because SWE is the dialect our country uses to talk to itself. African Americans who’ve become successful and important in U.S. culture know this; that’s why King’s and X’s and Jackson’s speeches are in SWE, and why Morrison’s and Angelou’s and Baldwin’s and Wideman’s and West’s books are full of totally ass-kicking SWE, and why black judges and politicians and journalists and doctors and teachers communicate professionally in SWE. Some of these people grew up in homes and communities where SWE was the native dialect, and these black people had it much easier in school, but the ones who didn’t grow up with SWE realized at some point that they had to learn it and become able to write in it, and so they did. And [INSERT NAME HERE], you’re going to learn to use it, too, because I am going to make you.

If this makes you too nauseated to think clearly, here is a good palliative post on Systemic White Ignorance. 

A good illustration of white ignorance can be found in George Yancy’s ‘Fragments of a Social Ontology of Whiteness.’ Yancy describes how a white philosopher whom he deeply respected cautioned Yancy with deep concern and out of good intentions not to get pegged as someone who pursues issues in African-American philosophy. Yancy immediately thinks,

‘Pegged! I’m doing philosophy!’ It immediately occured to me that the introductory course in philosophy that I had taken with him some years back did not include a single person of color. Yet he did not see his own philosophical performances—engagements with European and Anglo-American philosophy as ‘pegged’; he simply taught philosophy qua philosophy. Such a philosophy only masquerades as universal.

In this illustration, race is a fundamental factor in the type of ignore-ance exhibited by the white philosopher.

[…]

willful ignorance involves a pattern of assumptions that privileges that dominant group and gives license to members of those groups ‘to be ignorant, oblivious, arrogant, and destructive’ all the while thinking themselves ‘as good’.