Eubulides of Miletus is best-known for the Sorites paradox:

The paradox goes as follows: consider a heap of sand from which grains are individually removed. One might construct the argument, using premises, as follows:

1,000,000 grains of sand is a heap of sand (Premise 1)
A heap of sand minus one grain is still a heap. (Premise 2)

Repeated applications of Premise 2 (each time starting with one fewer grains), eventually forces one to accept the conclusion that a heap may be composed of just one grain of sand…

Will Wilkinson uses the Sorites paradox to construct a novel defense of anti-discrimination law:

I used to think that if negative rights to non-interference were
strictly observed, liberty was guaranteed, but I don’t now. Here’s how I
had thought about the matter. One racist acting in a private capacity
on his or her racist beliefs can’t violate anyone’s legitimate, negative
rights. (No one is entitled to another’s good opinion!) Two racists
acting as private citizens on their racist beliefs can’t violate
anyone’s rights. Therefore, I inferred, thousands or millions of racists
acting non-coercively on their racist beliefs can’t coercively violate
anyone’s rights. I now think this is quite wrongheaded.

My immediate reaction: Why draw the line at actions motivated by racism?  It seems like on Will’s logic, the same applies to actions motivated by Christianity, lookism, environmentalism, patriotism, or any other widely-held position.  Indeed, why draw the line at actions?  Since people care about others’ beliefs, it seems like beliefs as well as actions are suspect.

Will continues:

I realised that actions that are individually non-coercive can add up
to stable patterns of behaviour that are systematically or structurally
coercive, depriving some individuals of their rightful liberty. In fact,
rights-violating structures or patterns of behaviour are excellent
examples of Hayekian spontaneous orders–of phenomena that are the
product of human action, but not of human design. This shift has led me
to see racism and sexism themselves as threats to liberty.  Racism and
sexism have come to matter more to me in that I have come to see them in
terms of the political value that matters most to me: liberty.

This seems like a strangely unpluralist position, especially for someone like Will.  Why not just say that private racism and sexism are expressions of liberty, but many expressions of liberty have undesirable consequences?  Why not say that the legality of racism and sexism exposes a tension between, say, meritocracy and liberty?

Will goes on:

And so I
have become much more sympathetic to policies that would limit
individual liberty in order to suppress patterns or norms of behaviour
that might pose an even greater threat to freedom. So I’ve become fairly
friendly toward federal anti-discrimination law, affirmative action,
Title 9, the works.

While I admire Will’s invocation of the Sorites paradox, I still think he was wrong to change him mind.  If state action against workplace racism and sexism is warranted, why not state action against racism and sexism in dating and marriage?  Why not state action against every group that workplaces shun: the ugly, the socially awkward, guys with facial tattoos?  Indeed, from Will’s standpoint, it seems like every artist who produces art that nobody wants to buy can justifiably accuse the world of “coercion.”

The obvious reply for Will, of course, is that it’s a matter of degree; we have to balance the liberty to negatively judge others against the liberty to not be habitually negatively judged.  For racism and sexism, the latter far outweighs the former.

This answer will no doubt appeal to defenders of the status quo, but it fails on multiple levels.  Most obviously: When prejudices are ubiquitous juggernauts, democracies don’t make them illegal!  If virtually everyone held a prejudice, who would vote to suppress it?  Virtually no one.  That’s why the ugly, the socially awkward, and guys with facial tattoos now quietly suffer: even nice, respectable people inwardly scoff when they complain.  If Will should be standing up for anyone, he should be standing up for these silent minorities. 

Think about it this way:  When discrimination is legal, to whom do its victims turn for protection?  The people who oppose that form of discrimination.  Under democracy, the continued legality of a form of discrimination shows that people who oppose that discrimination are rare and marginalized.  The continued illegality of a form of discrimination, in contrast, shows that people who oppose that discrimination are common and influential.*

The upshot: Will’s framework may give him a good reason to support a long list of eccentric discrimination laws that our democracy will laugh out of court.  But his framework gives him little reason to support the discrimination laws our democracy has actually adopted.

* If opposition to workplace racism and sexism is so common and influential, why does it persist after fifty years of illegality?  Largely because the war on “racism” and “sexism” deliberately overlooks a long list of reasons why races and sexes objectively differ in job performance.

P.S. If you’re sure that standard racism and sexism are the most injurious of all prejudices,  ponder the vast number of people against whom discrimination is not merely permissible but mandatory.  To quote Proudhon, “That is government; that is its justice; that is its morality.”