Why would you stir rather than shake a cocktail?

Gnomon

If you shake a cocktail, the crushed ice melts, diluting the cocktail. If you stir, the ice will remain as ice, cooling the cocktail and only gradually diluting it, so the first taste, which is the one that is most important, will have a good strong flavour. Feb 12 04, 7:35 AM

jbean

Shaken cocktails usually contain ingredients that don't usually hang out together, such as fruit juices and bar sugars, and the melting of the ice is desirable, as in coladas and the like. Shaken drinks are normally strained to remove any large pieces of ice and served in a stemmed glass to help them stay cold longer. Stirred drinks are stirred more for the chilling effect than for mixing. Feb 12 04, 6:46 PM