Hello
The bit you quote is from Paradox 10, "Illusions for the maintenance of imperfect weapons & false fights", which begins "First, for the rapier (says the Italian, or false teacher)...". So this isn't what Silver himself believes, it is an argument of the "false teachers".
If you look more closely at the sword in the picture you'll see that while it does have a cross, it also has at least a knucklebow. Silver wouldn't be using a mortuary sword, which was after his time; it would be an early English basket hilt, like the Mary Rose sword (which also has a cross).
Silver thinks it is essential to have a "close" or "single" hilt - what we call a basket hilt, essentially - because he complains that rapiers and typical short swords (arming swords) of his time "have no hilts" (!) and don't provide enough protection for the hand, even though they have cross-guards at the very least, and usually quite complex hilts.
Cheers and good luck. Silver can be very confusing.
