 The second development derives from the phenomenal intentionality theory. Advocates of the idea of phenomenal intentionality seek to ground the intentionality of mental states in phenomenal consciousness, the subjective, experiential features of those states. According to this view, phenomenal intentionality is basic, with any other forms of intentionality derivative upon this basic form (Horgan &amp; Tienson 2002, Loar 2003, Kriegel 2013). According to many articulations of the phenomenal intentionality theory (e.g., Siewert 1998; Kriegel 2007, 2011; and Farkas 2008), the content of your thought and that of your twin is the same and that content is narrow. These attempts to construct a viable notion of narrow content have been systematically criticized by Yli-Vakkuri and Hawthorne (2018). If they are correct, there is no form of content that can be easily cordoned off from the world, and a thoroughgoing form of content externalism must, therefore, be true. (See entry on  narrow mental content  for more detailed discussion).