On guilt by association

When is guilt by association not a fallacy? I ask because of two things I���ve seen recently.

The first is Daniel Hannan���s fear that we���re heading for ���absolutely the most harmful outcome imaginable��� of Brexit, ���namely leaving the Single Market while keeping the Customs Union.��� He tries to blame everybody but himself for this, to which Jonn Elledge replies: ���it is not enough to blame your opponents for the world���s failure to live up to your fantasies.���

The second example is David Goodhart���s claim that the treatment of Windrushers is an outrage. To this, Jonathan Portes accuses him of ���astonishing hypocrisy��� as Goodhart was ���one of the most vocal cheerleaders for the "hostile environment" from the beginning, knowing full well what it would mean.���

In both cases, their opponents accuse Hannan and Goodhart of a form of guilt by association. Hannan���s support for Brexit, his opponents say, associates him with the fiasco we have, whilst Goodhart���s anti-immigrationism, it is alleged, implicates him in the Windrush scandal; Goodhart denies this by saying he���s not responsible for bad implementation.

Let���s take an obvious example of the guilt by association fallacy: ���how can you be a vegetarian? Hitler was a vegetarian!��� This has exactly the same structure as: ���how can you support Brexit when it is also supported by little Englanders and racists and will be implemented by buffoons?��� Or: ���how can you support the hostile environment policy when it���s supported by racists and implemented by [insert derogatory adjective here]?���

So, if my first example is an obvious fallacy, why aren���t by second and third examples?

The answer is that sometimes association has information value. When it does, guilt by association is not a fallacy.

���Hitler was a vegetarian��� tells us nothing about the merits or demerits of vegetarianism. However, the fact that a policy is supported by racists and will be implemented by people who fall well short of angelhood does have information value: it alerts us to the type of policy we���ll get.

In saying this, I���m not using hindsight. Just before the referendum I wrote:

Some of you have a vision of a Britain outside the EU that is a free, liberal, socialistic country. These are ideals with which I have sympathy. But we are kidding ourselves if we think a vote for Leave will be a move towards such a society. Instead, it���ll be a mandate for Farage and the inward-looking, reactionary mean-spirited philistinism he embodies.

And later in 2016 I said of immigration targets that:

if you give power to the state it���ll be misused, because the actually-existing state is a stupid bully. Just as ���anti-terror��� laws have been used to harass journalists and peaceful protestors, so immigration controls will hurt decent people. And for the same reason - because they are the softest targets.

If someone of my limited cognitive skills could see this, I���d expect others to do so.

Critics of Hannan and Goodhart, therefore, are right. The fact that their causes are associated with bad people was a strong clue that they were indeed bad ideas.

Many of you, I guess, will be with me so far.

But here���s the thing. You can make exactly the same criticism of me. I support much of Labour���s economic policy, especially anti-austerity and backing for coops. To this, some will ask: how can I do so, given that such policies are also supported by anti-Semites, big staters and various cranks and fanatics?

My answer is that these are a much smaller fraction of Labour supporters than were (say) little Englanders and neo-racists of Brexit, and so the information value of crankish support for such policies is low. But I���m not 100% confident in this answer.