Recent writers on philosophy have produced a number of arguments for the view that human consciousness and purposive action cannot be causally explained and are not suitable matters for scientific investigation. The main concern of this book is show that noen of these arguments is sound. The topics discussed include behaviourism, especially in relation to Wittgenstein’s private-language argument; the concepts of desire, will, and intention; the relation between causes, reasons, and purposes; the mind-brain identity theory; the freedom of the will; and what constitutes personal identity.