Tallis has found himself opposed to three of the important intellectual trends or fashions of the past two or three decades and his criticisms have been as little noticed as they have been worth noticing. He is like a boy who has seen the nakedness not of one emperor, but of three.

His first major intellectual assault was on post-modernism, the theory that has had the practical effect of turning literary scholarship in universities into third-rate philosophising and probably discouraging students from enjoying literature.

In his books, In Defence of Realism (Hodder Arnold, 1988), Not Saussure (Palgrave Macmillan, 1988) and Theorrhoea and After (St Martin's Press, 1998), he exposed the philosophical incompetence and elementary misunderstandings of the post-modernists, who did not deign to notice or reply to his attacks. 

The books, however, have been of immense value to those (including academics who wanted to swim against the tide) who sensed that there was something wrong, and not merely false but fraudulent, about post-modernism, but were not sufficiently up in philosophy to know exactly what it was.

While Tallis has been a fierce defender of rationality in general, and the rationality of science in particular, he has been an equally fierce opponent of the kind of scientism, or neurotheology  as he calls it, of the Daniel Dennett variety. Dennett claims not only that consciousness can be adequately explained neurophysically and neurochemically, but that consciousness isn't all it's cracked up to be in the first place. Dennett's view is no better or more sophisticated, fundamentally, than that of the 19th-century German materialists, who claimed that the brain secreted thought like the liver secreted bile. He has no more serious and severe a philosophical critic than Tallis.

Tallis criticises facile Darwinism on the same kind of grounds. The development of consciousness introduced something quite new into the world, and it is no good trying to fit it into a procrustean bed of preconceptions. As if all this were not enough, Tallis has written novels, plays and poetry, which have been highly regarded. So prodigious has been his output — and the quality of his output — that would one would like to report that he has terrible defects of character. Unfortunately, this is not so. Moreover, he is possessed of a brilliant wit. I once telephoned him to ask a technical question about the possibility of the paternal transmission of congenital syphilis in Ibsen's play, Ghosts. 

Ibsen, in later years, read nothing but newspapers, but it so happened that the most eminent French syphilologist of the day, Alfred Fournier, had suggested the year before Ibsen wrote the play that fathers could pass on syphilis through the semen without infecting the mother.

Quick as a flash, Tallis said, "Shouldn't that be Forniquer?"