This 19thC bookplate shows just how books were valued by their previous owners, it reads;
"If thou art borrow'd by a friend,
Right welcome shall he be,
To read, to study, not to lend,
But to return to me.
Not that imparted knowledge doth,
Diminish learning store,
But books I find when often lent,
Return to me no more".
Read slowly; pause frequently; think seriously;
with the corners of the leaves not turned down.
Just about sums it up for me that does!