Our understanding of what exactly needs protected against in order to safeguard a plausible construal of our 'freedom of thought' is changing. And this is because the recent influx of cognitive offloading and outsourcing-and the fast-evolving technologies that enable this-generate radical new possibilities for freedom-of-thought violating thought manipulation. This paper does three main things. First, I briefly overview how recent thinking in the philosophy of mind and cognitive science recognises-contrary to traditional Cartesian 'internalist' assumptions-ways in which our cognitive faculties, and even our beliefs, can be materially realised by as well as stored nonbiologically and extracranially. Second, and taking brain-computer interface technologies (BCIs) and the associated possibility of 'extended' beliefs as a reference point, I propose and defend a sufficient condition on freedom-of-thought violating (extended) thought manipulation. On the view proposed, the right not to have one's thoughts or opinions manipulated is violated if one is (i) caused to acquire non-autonomous propositional attitudes (acquisition manipulation) or (ii) caused to have otherwise autonomous propositional attitudes non-autonomously eradicated (eradication manipulation). The implications of this view are then illustrated through four thought experiments, which map on to four distinct ways-what I call Type 1-Type 4 manipulation-in which, and with reference to the view defended, one's freedom of thought is plausibly violated.
2.It is tempting to think the answer to these questions is 'no' 4 , given how pervasive the Cartesian picture of the mind, as a kind of private 'inner theatre' , remains in ordinary thought and talk, as well as, implicitly, in legal and political thinking. 5 On the Cartesian view, according to which a thinker alone has privileged and exclusive access