Many philosophers believe that there is a causal condition on perception, and that this condition is a conceptual truth about perception. A highly influential argument for this claim is based on intuitive responses to Gricean style thought experiments. Do the folk share the intuitions of philosophers? Roberts et al. (2016) presented participants with two kinds of cases: Blocker cases (similar to Grice’s case involving a mirror and a pillar) and Non-Blocker cases (similar to Grice’s case involving a clock and brain (...) stimulation). They found that a substantial minority agreed that seeing occurs in the Non-Blocker cases, and that in the Blocker cases significantly less agreed that seeing occurs. They thus hypothesized that folk intuitions better align with a no blocker condition than with a causal condition. This paper continues this line of enquiry with two new experiments. The paper investigates the generality and robustness of Roberts et al.’s findings by expanding the sense modalities tested from only vision to audition and olfaction as well. The paper also uses Gricean style thought experiments as a case study for investigating the “reflection defense” against the negative project in experimental philosophy. Our results replicate and extend Roberts et al.’s study and support their hypothesis that folk intuitions better align with a no blocker condition. They also provide an empirical reason to doubt the reflection defense. (shrink)

The increasing availability of DNA-based diagnostic tests has raised issues about whether these should be applied to the population at large in order to identify, treat or prevent a range of diseases. DNA tests raise concerns in the community for several reasons. There is the possibility of stigmatisation and discrimination between those who test positive and those who don't. High-risk individuals may be identified for whom no proven effective intervention is possible, or conversely may test "positive" for a disease that (...) does not eventuate. Controversy concerning prenatal diagnosis and termination of affected pregnancies may arise. Haemochromatosis, however, is a disease that is not only treatable but also preventable if those at high risk are identified presymptomatically. This paper will identify and discuss key issues regarding DNA-based population screening for haemochromatosis, and argue that population-based genetic screening for haemochromatosis should be supported when a number of contentious issues are addressed. In the context of a health system with limited resources haemochromatosis is the paradigm of a disorder where there is an ethical and clinical imperative to encourage presymptomatic DNA testing for all in ethnically relevant communities. (shrink)