If design patterns are not supposed to produce reusable code then why use them?

I have recently been engaged in an argument via email with someone who criticises my low opinion of design patterns (refer to http://www.tonymarston.net/php-mysql/design-patterns.html ). He says that design patterns are merely a convention and not a reusable component. My argument is that something called a pattern is supposed to have a recurring theme, some element of reusability, so that all subsequent implementations of a pattern should require less effort than the first implementation. If design patterns do not provide any reusable code then what is the point of using them? I do not use design patterns as I consider them to be the wrong level of abstraction. I am in the business of designing and developing entire applications which comprise of numerous application transactions, so I much prefer to use transaction patterns (refer to http://www.tonymarston.net/php-mysql/design-patterns-are-dead.html and http://www.tonymarston.net/php-mysql/transaction-patterns.html ) as these provide large amounts of reusable code and are therefore a significant aid to programmer productivity. What is your opinion? Are design patterns supposed to provide reusable code or not? If not, and each implementation of a pattern takes just as much time as the first, then where are the productivity gains from using design patterns? -- Tony Marston http://www.tonymarston.net http://www.radicore.org