The Four Elements

Elements of processes and programs seem to be grouped or ordered in fours:

• Planning, Testing, Programming and Releasing are four elements encountered in IterationPlanning
• KentBeck lists ProgrammingEssentials as Coding, Testing, Listening, Design.

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Others:

The first PeriodicTable? (Chinese, over 3000 years old); the five elements:

  Wood
  Water
  Fire
  Metal
  Earth

The second PeriodicTable? (the Chinese was first, and directly inspired the Greek):

 Air
 Fire
 Water
 Earth

The above are not periodic, so in what sense are they first and second? And how could the Chinese elements have directly inspired the Greek elements, when the two cultures were not in direct communication?

Because there was in fact limited contact between east and west, see e.g. http://www.ess.uci.edu/~oliver/silk.html Note however that there are no oceans in the way, so sporadic contact between the regions presumably goes back indefinitely far. Also we are talking about information transmission, which can happen via a diffusion model indirectly without even the need for direct contact.

I'm well aware of indirect contact between the two cultures. The silk road was generally too late to explain this particular list, however, as were the Greek conquests in the Middle East. It could have diffused through Persia, but it would be odd for them not to have left their own distinct stamp on the ideas, and in any case that's not direct inspiration. I would love to see some evidence about how the two sets of elements are related.

As with the modern Mendeleyev-based "period table of the elements", each of these systems was considered to constitute the atomic elements from which all else in the world was formed. In that sense, all three are identical in purpose and function. The issue of "periodicity" is a non-issue in this context, and could be very seriously nitpicked even in the modern table. Elements, yes; atomic, no; periodic, no; table, no.

• Look again. The greeks knew about atoms, so atomic yes. Periodic here means cyclical, which is what both the greeks and the chinese meant. And to show the periodicity these things were usually shown in diamond form, not as linear lists, so it's also "table, yes".

• The Greeks believed in the four elements long before they came up with atoms, and Greek philosophers like Democritus generally considered all atoms to be identical. So no, they're not atomic. And the Chinese elements are definitely neither atomic, nor presentable in diamond form.

The modern table has some periodic aspects. The above are really lists, rather than tables.

[Some random person called the greek version a periodic table. I continued using the name when I corrected the text to say chinese first greek second. These nitpicks are (1) wrong (2) I don't really care. It's just a name.]

FourLayerArchitecture

 The ViewLayer?.  
 The ApplicationModelLayer? 
 The DomainModelLayer?
 The InfrastructureLayer?

FourLevelsOfCompetence

 The Kirkpatrick Model by Donald L. Kirkpatrick  
  Unconscious Incompetence = you don't know that you can't do it well. 
  Conscious Incompetence = you know you can't do it well. 
  Conscious Competence = you do it well, and you think about the work as you do it. 
  Unconscious Competence = you're so successful it's "automatic" -- you do it well, without thinking about it. 

FourProcessesOfConsciousness

  Perception, Thought, Action, Feedback 

FourQuadrants

  from book SevenHabitsOfHighlyEffectivePeople by StephenCovey 

FourVariables

 Resources, Scope, Quality, Time 
 FourVariablesUnderStress 

FourBlankCards

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What on earth is this page about? Four is just one of a limited number of small natural numbers. Singularities, Pairs, Triplets and groups of 5,6,7,8,9 and 10 are just as widely used.