"The Certainty of Perceptual Knowledge Claims" Revisited

My doctoral thesis for the PhD in Philosophy at New York University, 1969 was just this--as I remember those years ago. 

What drew me back in memory was the astounding realization that after my thesis was accepted, the philosophical problem that it was attempting to handle just about disappeared from discussion!

In it I attempted to argue against A.J. Ayer's formulation of the problem--that perceptual evidence was needed--not simply could be produced as any perceptual knowledge claim could warrant--on behalf of something about reality.  The point I was trying to make is that in ordinary parlance and typical perception, no substantiation from sensational evidence is appropriate, simply because the claim, e.g., "I see the book," is certain, as certain as any perceiver could believe.  Such knowledge claims are self-evidently true; and no further justification is in order, though reference to sensational evidence is always possible, as is necessary when one judges that railroad tracks converge in the distance based on his perceptual gaze.

So much for that.  I thought it was something to point out that a grad student in philosophy could make a case that perceptual evidence is not needed when a distinguished professor like Ayer seemed to think otherwise!