Pipistrello's Commonplace Book

There are three things no man but a fool lends, or, having lent, is not in the most hopeless state of mental crassitude if he ever hope to get back again. These three things are - Books, Umbrellas and Money.  Douglas Jerrold

It may help to recall the bon mot I heard from a Russian physicist: 'Proofs in physics follow the standards of British justice and hold the accused innocent until proved guilty. Proofs in mathematics follow the standards of Stalinist justice and hold the accused guilty until proved innocent.' A footnote from T. W. Körner's The Pleasures of Counting,  1996