(via @AdrianRossouw)

%% The Two Aspects

Below the surface of the machine, the program moves. Without effort, it expands

and contracts. In great harmony, electrons scatter and regroup. The forms on the

monitor are but ripples on the water. The essence stays invisible below.

When the creators built the machine, they put in the processor and the memory.

From these arise the two aspects of the program.

The aspect of the processor is the active substance. It is called Control. The

aspect of the memory is the passive substance. It is called Data.

Data is made of merely bits, yet it takes complex forms. Control consists only

of simple instructions, yet it performs difficult tasks. From the small and

trivial, the large and complex arise.

The program source is Data. Control arises from it. The Control proceeds to

create new Data. The one is born from the other, the other is useless without

the one. This is the harmonious cycle of Data and Control.

Of themselves, Data and Control are without structure. The programmers of old

molded their programs out of this raw substance. Over time, the amorphous Data

has crystallized into data types, and the chaotic Control was wrung into control

structures and functions.

%% Short Sayings

When a student asked Fu-Tzu about the nature of the cycle of Data and Control,

Fu-Tzu replied 'Think of a compiler, compiling itself.'

A student asked, 'The programmers of old used only simple machines and no

programming language, yet they made beautiful programs. Why do we use

complicated machines and programming languages?' Fu-Tzu replied 'The builders of

old used only sticks and clay, yet they made beautiful huts.'

A hermit spent 10 years writing a program. 'My program can compute the motion of

the stars on a 286-computer running MS DOS,' he proudly announced. 'Nobody owns

a 286-computer or uses MS DOS anymore,' Fu-Tzu responded.

Fu-Tzu had written a small program that was full of global state and dubious

shortcuts. Reading it, a student asked 'You warned us against these techniques,

yet I find them in your program. How can this be?' Fu-Tzu said, 'There is no

need to fetch a water hose when the house is not on fire.' {This is not to be

read as an encouragement of sloppy programming, but rather as a warning against

neurotic adherence to rules of thumb.}

%% Wisdom

A student was complaining about digital numbers. 'When I take the root of two

and then square it again, the result is already inaccurate!' Overhearing him,

Fu-Tzu laughed. 'Here is a sheet of paper. Write down the precise value of the

square root of two for me.'

Fu-Tzu said, 'When you cut against the grain of the wood, much strength is

needed. When you program against the grain of a problem, much code is needed.'

Tzu-li and Tzu-ssu were boasting about the size of their latest programs.

'Two-hundred thousand lines,' said Tzu-li, 'not counting comments!' Tzu-ssu

responded, 'Psah, mine is almost a *million* lines already.' Fu-Tzu said, 'My

best program has five hundred lines.' Hearing this, Tzu-li and Tzu-ssu were

enlightened.

A student had been sitting motionless behind his computer for hours, frowning

darkly. He was trying to write a beautiful solution to a difficult problem but

could not find the right approach. Tu-Tzu hit him on the back of his head and

shouted, '*Type something!*' The student started writing an ugly solution. After

he had finished, he suddenly understood the beautiful solution.

%% Progression

A beginning programmer writes his programs like an and builds her hill, one

piece at a time, without thought for the bigger structure. His programs will be

like loose sand. They may stand for a while, but growing too big they fall apart

{Referring to the danger of internal inconsistency and duplicated structure in

unorganized code.}.

Realizing this problem, the programmer will start to spend a lot of time

thinking about structure. His programs will be rigidly structured, like rock

sculptures. They are solid, but when they must change, violence must be done to

them {Referring to the fact that structure tends to put restrictions on the

evolution of a program.}.

The master programmer knows when to apply structure and when to leave things in

their simple form. His programs are like clay, solid yet malleable.