Parmenides matters not just for philosophy. One of the effects of the moribund state of intellectual enquiry that Tallis worries about is found in science. Physics is reaching an 'arrest of understanding', in say the extremes of string theory. Or in neurobiology, the study of consciousness has hit a brick wall, for all that its exponents engage in elaborate strategies of denial: we are being led towards a third-person understanding of ourselves, when we have first-person consciousness; as if we were machines not minds. That is dangerous.
Another part of Tallis' concern is that along with this scientism, though diametrically opposed to it, comes an 'oppressive supernaturalism'. You see it in the confrontation between bleak, deterministic Darwinism and fundamentalist, Christian creationism. They compete for the right to respond to our deepest human needs, to understand, forcing out the infinitely more subtle Parmenidian spirit in the process.