 Two further kinds of necessity are available: metaphysical and logical. Now, many philosophers (largely influenced by the zombie idea) believe the connection from physical facts to consciousness cannot be logical even in a broad sense. And certainly the conceptual scheme of physics does not appear to enable logical links from the physical to the experiential or phenomenal (see e.g. Kriegel 2011; Stoljar 2006). However, some argue that nevertheless zombies are not really conceivable at all (Kirk 2005, 2008, 2013; Tye 2006); Kirk (2013) also maintains that although the physical facts do not entail the truth about conscious experience a priori, they nevertheless entail it by logical necessity. 