 ST has sparked a lively debate, which has been going on since the end of the 1980s. This debate has dealt with a great number of theoretical and empirical issues. On the theoretical side, we have seen philosophical discussions of the relation between ST and functionalism (Gordon 1986; Goldman 1989; Heal 2003; Stich &amp; Ravenscroft 1992), and of the role of tacit knowledge in cognitive explanations (Davies 1987; Heal 1994; Davies &amp; Stone 2001), just to name a few. Examples of empirical debates are: how to account for mindreading deficits in Autism Spectrum Disorders (Baron-Cohen 2000; Currie &amp; Ravenscroft 2002), or how to explain the evolution of mindreading (Carruthers 2009; Lurz 2011). It goes without saying that discussing all these bones of contention would require an entire book (most probably, a series of books). In the last section of this entry, we confine ourselves to briefly introducing the reader to a small sample of the main open issues concerning ST.