How did Aristotle come to
his a priori, intuitive conviction that material
bodies actually exist? "How? By knocking his sconce against
them, sure." Stephen here is fictively allying Aristotle with
the 18th century man of letters Samuel Johnson, who had no
patience for Bishop
Berkeley's "ingenious sophistry" (in the words of James
Boswell) "to prove the non-existence of matter, and that
everything in the universe is merely ideal." Asked to refute
Berkeley's position, Johnson did so physically rather than
argumentatively.
Boswell writes, "I shall never forget the alacrity with which
Johnson answered, striking his foot with mighty force against
a large stone, till he rebounded from it, 'I refute it thus.'"
Adding his own thought experiment to Johnson's stone-kicking
and Aristotle's noggin-knocking, Stephen thinks, "If
you can put your five fingers through it it is a gate, if
not a door. Shut your eyes and see." The sense of
touch can confirm things that vision may leave ambiguous.
The allusion to Boswell's Life of Johnson was first
noticed by Robert M. Adams, in Surface and Symbol: The
Consistency of James Joyce's Ulysses (Oxford, 1962),
134.