Seeing for the first time somebody wearing a strange cap and being connected via multiple cables to a computer and obviously giving instructions to a technical device without moving even a finger is probably impressive for almost everybody. One could easily become convinced that a ‘mind-reading machine’ is at work here and that the idea that the thoughts of human beings might be ‘seen’ from outside has now finally come true: Just by using – what else?! – a computer. That thinking is the core human faculty and thus the prime human way of doing something is in line with at least some of the most important European traditions in philosophy and religion. If the brain–computer interface (BCI) was a way to shortcut theory and practice, to take away the persistent dialectic between these two poles of human existence, they would without doubt be the most philosophical devices ever. However, learning more about BCIs makes things different. Understanding that current BCIs use only ‘dull’ signals without any semantic content leads to a disappointment – measured by the dramatic mind-reading impression one had before – but this is a necessary disappointment. While an unrealistic understanding of BCIs raises many of the most spectacular questions in ethics and metaphysics, the real existing BCIs render them inadequate and require rather sober and detailed work in applied ethics and philosophical anthropology.