5.2 Assumptions and argument maps

Claims do not exist in a vacuum. When we come to judge how one claim relates to another claim, we rely on unspoken assumptions or beliefs. If these assumptions are shared by the claim maker and their audience, there is no need to state them explicitly and so they remain unspoken or implicit.

In Section 4, the author of the ‘Tor stinks …’ slide and its intended audience are all members of an intelligence community. They are tasked with tracking people who may pose a threat to society. This audience will share the belief that anything that prevents them from doing so is a problem. This shared belief doesn’t need to be stated explicitly – it is an unspoken assumption between members of the intelligence community. But the belief is crucial when we interpret [the intelligence community] will never be able to de-anonymize all Tor users all the time as supporting the claim that Tor stinks.

To see this, now consider an audience of hackers, journalists or human rights activists. They are unlikely to be persuaded by the argument that Tor stinks … because [the intelligence community] will never be able to de-anonymize all Tor users all the time. On the contrary, they may view the statement [the intelligence community] will never be able to de-anonymize all Tor users all the time as opposing the claim that Tor stinks.

Why bring this up in the context of sharing maps on the internet? When you read such maps, you need to be alert to the fact that the assumptions of the authors may be different from yours. As a result, you can’t just uncritically take the content of such maps for granted.