Daniel Dennett’s debt to Wittgenstein is well known and acknowledged by him. Wittgenstein believed that language had limits and that philosophy could not and should not try to express ideas beyond those limits. Dennett believes that subjective mental states and processes are beyond the reach of scientific investigation and that he can therefore ignore them.
Dennett’s deterministic bias makes this a convenient area of neglect for his thought. If individual subjective conscious experience exists--which it manifestly does--then free will is virtually established by that fact alone, a conclusion that Dennett and the other new atheists cannot stomach. Dennett is at heart a verificationist and behaviorist in disguise and barely bothers to contest these characterizations. In Appendix A to “Consciousness Explained,” he merely states that (to paraphrase his quote from Wittgenstein) he is “grammatically” a behaviorist and leaves it at that rather coy response.
Given Dennett’s determinist/verificationist/behaviorist stance, his position that subjective experience has little scientific value is already compelled without any need for further investigation. And he feels largely free to ignore or neglect it just as humans do the blindspots in their own visual field. For those misguided ideologies ignore subjective mental experience as an ideological premise and therefore allow no meaningful possibility to discuss the subject. As Wittgenstein might say, such subjective individual experiences are beyond the limits of language to express. In fact they are merely beyond the self-imposed mental limitations of Daniel Dennett.