The programmer, like the poet, works only slightly removed from pure thought-stuff. He builds his castles in the air, from air, creating by exertion of the imagination. Few media of creation are so flexible, so easy to polish and rework, so readily capable of realizing grand conceptual structures.

Einstein repeatedly argued that there must be simplified explanations of nature, because God is not capricious or arbitrary. No such faith comforts the software engineer.

A basic principle of data processing teaches the folly of trying to maintain independent files in synchonism.

Plan to throw one (implementation) away; you will, anyhow.

Systems program building is an entropy-decreasing process, hence inherently metastable. Program maintenance is an entropy-increasing process, and even its most skillful execution only delays the subsidence of the system into unfixable obsolescence.

Successful software always gets changed.

Product procedure...must securely protect the crown jewels, but, equally important, it must eschew building high fences around the garbage cans.