Category Archives: Philosophy of Engineering

Truth (and Beauty) are Useless, Seek “Good” instead

Beauty, Truth, or Goodness?  In a previous article I wrote called ‘Twilight of the Idols’, we learned (from Nietzsche) that truth is not a useful concept to designers and structural engineers.   Let science (or religion, for that matter), have ownership of truth.  We can do ‘truth’ in our spare time.  We also have learned (from manifesto on goals being useless), that beauty is a by-product of our work, not something we need to consciously drive towards.   What is left?  Goodness.  Quality.  We should focus in this arena of Plato’s Trinity, not the other two.

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We design buildings, bridges and other structures, but how do we do this well or how do we improve over time?   Does our conception of the structure to be built change with experience and improve?   Yes, we learn what is feasible and what is practical with experience but what about Quality?  When we develop options for consideration or make a decision based on a certain amount of information, how do we choose the best option and make the best decision?

The entries in the Manifesto blog herein, are some attempts at improving design, and many others have written on the subject for structural engineers.  For example, David Billington in The Tower and the Bridge, described how the best designers of the past made engineering decisions based on a balance of efficiency, economy and elegance.  We can add to those considerations such as durability, constructability along with  resilience and sustainability.  Also, when thinking about quality, we can do this in two ways, the end (the structure itself), and the process (the design process).  We can say to ourselves “I want quality in the form of the structure and the assemblage of materials” or “I want to design well, I want to be good at engineering decision making”.    These may overlap.  For example, how does the description or idea of the final artifact as “quality”, create a path for working towards it?   After all, we are typically designing new and novel things (i.e.. not pancakes that we can taste, recook and/or adjust ingredients easily).

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In may be worth investigating what the Philosophers of antiquity thought on the subject of quality, beauty, and art.   I found that a terrific anthology to get a good background on this subject is Hofstadter’s Philosophies of Art and Beauty: Selected Readings in Aesthetics from Plato to Heidegger.  In it we find the beginnings of our conception of quality.  For example, we find that Aristotle, in his Parts of Animals Book I believes that one has to have a clear picture of the structure first (the end), and simply work towards that.

He starts by forming for himself a definite picture, in the one case perceptible to the mind, in the other sense of his end – the builder of a house – and this he holds forward as the reason and explanation of each subsequent step he takes.  Art indeed consists in the conception of the result to be produced before its realization in material… The plan of the house has this or that form; and because it has this or that form, the construction is carried out in this or that manner.  For the process of evolution is for the sake of the thing finally evolved, and not this for the sake of the process. (Aristotle, Parts of Animals Book I, 640).

But how does one conceive of an end first?    How does one know ahead of time that something will be good, correct and well proportioned or efficient and economical?   Here we learn from Aristotle, that good design is done by those who can take a complex task and split it up into smaller and simpler problems.  One step at a time.   Engineers are pretty skilled at this.   It may also be that when a good engineer has a vision, or an end to be aimed at, he/she has a command of measure (what we now may think of as proportion).  The engineer, according to Plato, must know the nature of measure for the proper portioning of structures (artistic as well as scientific).  Measure for Plato, is essential to quality and is the fundamental principle that defines quality.  A column should be this size, not that, for many reasons.

Basic to any art, is the art of measure without which there can be no art at all.  For to know the proper size of a column, proportion of a window, the proper organization of language in a poem, is to command the art of measurement…. There are accomplished men, Socrates, who say…the art of measurement is universal, and has to do with all things.” (Plato, Statesman 285b)

So if we think we succeeded in the proper form by creating something well proportioned, how do we know we are right?  How do we judge quality?

Every art does its work well – by looking to the intermediate and judging its work by this standard. (Aristotle, Nicomachean Ethics Book II 1106)

He agrees that the science may have a hand in the judgment of art.

The chief forms of beauty are order and symmetry and definiteness, which the mathematical sciences demonstrate in a special degree. (Aristotle, Metaphysics Book XIII 1078)

So we can learn a bit about what Aristotle and Plato thought about how to conceive and judge quality structures, but we have learned less about the individual engineering designer.   It is the engineer’s personal ability that contributes to great work. The engineer that seeks personal excellence will see that transcend themselves and into the built world.  It may be obvious that all designers aim for quality structures as Aristotle suggests in his opening to Nicomachean Ethics.

Every art and every inquiry, and similarly every action and pursuit, is thought to aim at some good; and for this reason the good has rightly been declared to be that which all things aim. (Aristotle, Nicomachean Ethics Book I 1094).

And to which all engineers should aim – but not aim towards goodness, it is not a goal, it is a way.  Here we are back to the process of design, how the individual designer takes action and aims at some good, or quality (and being good is integral to this, but not going there).  It a process that requires constant reflection and the way to create safe, economical and efficient structures and do it better and better over time.

We know that the design of structures combines the objective science (material mechanics) with more complex subjective decision making requiring sound judgment (heuristics). Problems encountered by the structural engineer are complex and nuanced and require experience and judgment to better sift through the multiple design ideas.  If you have been reading this blog, one recurring theme is that idea that engineering is more of an art than a science.   Not art as beauty or aesthetic vision, not at all.  Again, that is useless.  In the forward to Nervi’s book Structures, Mario Salvadori says it best when describing one of the greatest structural engineers of the 20th century:

Nervi’s results are not achieved by consciously trying to meet aesthetic demands, but by tackling the fundamental structural problems from the outset, and giving them an obvious and clearly articulated solution.  Beauty, says Nervi, is an unavoidable by-product of this search for satisfactory structural solutions.  [Salvadori 1956:  vi]

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So no answers or short cuts to quality, just more questions.  The original of my poem on Nervi called  “The Structure That Sings” (later published in STRUCTURE) has a similar conclusion (beauty as an end and not sought after)…


There is something called “design science” (bio-mimicry, form finding, geodesic geometry, etc) which has mathematical, scientific, and objective procedures to create form.  So “truth in form” is okay –  but again, it is very rare that good design is driven by scientific methods.   It can be, but more often not.   So, if I could re-write this, I would replace “truth in form as a means”, with “quality as the means”.   Quality, is by definition, process.   As Pirsig would say, quality is “the knife edge of experience”, and living in it and with it, beauty just becomes.

Listening is an underrated sense to us Engineers

Seth Horowitz, an auditory neuroscientist at Brown University and the author of “The Universal Sense: How Hearing Shapes the Mind”, wrote a terrific article in the New York Times called The Science and Art of Listening which starts…

“Here’s a trick question. What do you hear right now?  If your home is like mine, you hear the humming sound of a printer, the low throbbing of traffic from the nearby highway and the clatter of plastic followed by the muffled impact of paws landing on linoleum — meaning that the cat has once again tried to open the catnip container atop the fridge and succeeded only in knocking it to the kitchen floor.”

The slight trick in the question is that, by asking you what you were hearing, I prompted your brain to take control of the sensory experience — and made you listen rather than just hear. That, in effect, is what happens when an event jumps out of the background enough to be perceived consciously rather than just being part of your auditory surroundings. The difference between the sense of hearing and the skill of listening is attention.   [Horowitz, NY Times 11/9/2012]

This trick of asking yourself what are you hearing right now, reminds us of the difference between listening and hearing.   Many of us have no trouble hearing sounds, but listening to meanings with our full attention is another matter.  Can we shut of our internal thoughts and really listen to our design team around us?   Can we listen to the Architect or Contractor or co-worker without assuming what they will say or without interruptions by our own thoughts?

Science is Applied Engineering

We were designing and building things long before we had a “scientific” methods and mathematical solution techniques – and we still do today.  Did we need to wait for mathematical understanding of a hanging chain before we could build catenaries?  Of course not.   We didn’t need to wait for Galileo and Bernoulli to create architecture.   We didn’t need Euler to design columns.  We as structural engineers should recognize that while science and math are critically important to what we do, they do not define us – and history tells us, they never did.  How can we be defined as applied scientists when engineering predates science?

I am particularly suspicious of the idea that our masterbuilders, craftmen, and masons of the past did not understand flexure and compression basics (top of beam is in compression for example or rules for column slenderness).    They may not have had the proper formulas but they certainly had a better intuition than we give them credit.  Yes, Leonardo Da Vinci and Galileo were the first to “discover” bending stress by writing it down, but it was used as rules of thumb by our builders well before that time.

In the book “Structural Engineering:  The Nature and Theory of Design” William Addis quotes the following statement from Karl Terzaghi challenging the idea that theorey leads to practice:

History shows us that there is hardly a single concept of practical importance in the field of structural engineering that was not instinctively anticipated and used with success in design and construction by individuals or groups of engineers many centuries before applied mechanics came into existence.

In Henry Petroski’s book Remaking the World, he states:

Some of the first modern engineers did not apply science but rather led science.  The science of thermodynamics may be viewed as an application of steam engines, and rational structural analysis as an application of bridge building.   The view of scientific discovery as depending on the ingenious craftsmanship of instruments, and thus following technology, convincingly flies in the face of the conventional wisdom that technology is mere applied science.  [Petroski, 1997, 17]

So according to this, Science is Applied Engineering

Structural Art – Heat Plant at Brown University

One of the finest examples of structural art in Providence is Brown University’s Heat Plant on Llyod Ave.  It is a hidden gem and combines the science of efficiency with the practice of economy and humility.   The brick facade is sawtooth in plan at the base and straight at the top, creating beautiful hyperbolic brick sections that are repeated throughout.


Nervi’s Aesthetics and Technology in Building

Like artists, Engineers want to create beautiful words – when appropriate –  as well as satisfying the science of efficiency and the art of economy.  Nervi (1956) states that in order to do that, ones simply needs to work honestly.

Every improvement in the functionality and the technical efficiency of a product brings out an improvement in its aesthetic quality . . . there is no doubt that any product of high efficiency is always aesthetically satisfying. In the field of architecture, in which functional, statical, and economic needs are intimately mixed, truthfulness is an indispensable condition of good aesthetic results. [Nervi, 1956]

In addition, it is the engineer’s personal ability that contributes to great works of structural art. The engineer that seeks personal excellence will see that transcend themselves into the built world – just like building with LEGOs as a kid, it just takes longer.

I remember visiting a project where I designed all the connections for a large box truss that supported four stories of concrete and spanned 100 feet. The erector and welder was proud to show me his work and described the installation, welds and details as a master craftsman would. He was not being self-serving—he was describing the work itself. He and I both knew that this was going to be covered up for no one else to see.  He was still deeply satisfied, as was I. I realized much later that the satisfaction was not really about the truss or even the workmanship (craft).  What he was really showing me was a manifestation of himself in the steel connection. The weld was beautiful and well-crafted, of course, and that was satisfying, too; but that is not really what he was feeling.  He was really showing me that he was a good human being; that he is quality just like the connection – he was virtuous.  The inanimate object was a reflection of him and it was beautiful. We can learn a great deal about how the outcome of our work is conceived in our minds the same way. While we are not particularly goal oriented, although we do see our work as a actively progressing towards “Quality” (in the present only – the future is unhealthy to think too much about). Just like this erector, we are not spectators. We like private concentration, working autonomously or in teams, and delivering quality work (not ourselves) to others.  The work is us, but that is our secret.  Maybe that is why virtue is the most important trait to engineers to contribute and create beautiful works.  Nervi thought so.

Objective Beauty and Fazlur Kahn

Last week, Structures Workshop was recommended for a very small project to a new client by the daughter of the great structural engineer Dr. Fazlur Kahn, Yasmin Kahn.    This was a great honor for us to be recommended by Yasmin, also a structural engineer and prolific writer. I found this picture of them: After learning about this, I started thinking about Dr. Fazlur Kahn and how much he contributed to my profession but also to the skyline of my hometown, Chicago.  I was mesmerized as a child living in the northern suburbs of Chicago by glimpses, on clear days, of the John Hancock and Sears Tower.  I wondered to myself if those memories contributed to my desire to one day become a structural engineer.  I wanted to learn more about Dr. Fazlur Kahn and recently bought the book Engineering Architecture: the Vision of Fazlur Kahn which was written by his daughter Yasmin Kahn.  I am reading it currently and it is a terrific book. To my delight, I have something in common with Dr. Fazlur Kahn.   When he was 29, in 1958, and living in East Pakistan, two of his favorite books were Will Durrant’s Story of Philosophy and George Santayana’s The Sense of Beauty.  I was about the same age when I read the The Sense of Beauty.  It was 2001 in my case, and I was working at Thornton-Tomasetti in New York City and taking Philosophy classes at the New School at night.  I remember The Sense of Beauty well – it was much easier than the other readings required for the Philosophy of Aesthetics course I was taking, and much better in many ways.  This was a time when I thought beauty was objective – it just needed to a part of Plato’s archetypal forms.  Since architectural beauty consisted of form and extension (today what we call proportion), then it is independent of subjects (unlike smell, taste, sound, touch).  Form could be part of “the thing in itself” (Kant’s Noumenal World as opposed to his Phenomenal World of mere appearances – i.e. Plato’s Cave).  I thought that if the beauty was related to form, then it could become objective and viewed within Schopenhauer’s “will” (as opposed to representation).  Another way to consider it objective is to say that beauty is part of Carl Jung’s “collective unconscious” (that is, beauty being a part the unconscious brain which is shared by all).   Then, saying that something is beautiful (or ugly) can be universally and collectively accepted as fact (if form and extension have independent realities from our selves).  I may have changed my view on this over time, but even so, I believe the Sears Tower and the John Hancock are objectively beautiful – and it is thanks to Dr. Fazlur Kahn.

Why Engineering Can Never be Codified

The code provides minimal information that is helpful to solve a particular problem. This is obvious to me as a practicing engineer so I get surprised when asked by some “what do you mean the code allows flexibility”, or “how can you say the code is of little importance”, or “I don’t understand you when you agree that the code is huge in content but will never help solve 95% +of problems we face”.   Allow me to explain. 

There are engineers (mostly academics who think wrongly that we are applied scientists) that actually believe structural engineering is just about stress and strain.  Let me respond to the main question about how engineering decision making is not procedural and can not be within codes by asking another question…

What do codes say about designing a simple steel beam?

Codes tell us not exceed 0.9 Fy Z for moment checks and something else for shear and that is about it.   Codes do not say anything about the following…

  • what is an optimum spacing of beams? 
  • how do I weigh economy vs efficiency -in other words should I use a lot of the same beam or optimize every beam for diff spans
  • should I consider camber and how to evaluate cost of camber vs increase size of beam without camber
  • constructability – should I make sure the girder is as deep or deeper than the beam even if the girder is a small span
  • should I evaluate the vibration of the beam
  • should I allow for shear tabs instead of double clips angles at the ends to save money in the details
  • while I am designing a beam to girder connection of the same depth, should I verify the connection works with a double cope by doing shear rupture and block shear calcs
  • should I verify the studs should be a max of 1 per foot, or go to 2
  • should I size the beam to be not composite
  • how do I evaluate costs of studs, etc
  • do I feel comfortable with a 1″ deflection even if the code allows it for this 30ft member or should I stick to my arbitrary 0.75″ I made up
  • should I evaluate the ponding of the concrete and add additional dead load when the beam deflects
  • is a wide flange the best solution for this or should I consider a channel instead
  • I decide for this beam I am unhappy about a previous job where I cambered the beam 1″ and the tolerance the fabricator is allowed increased that to 1.5″ and the SC connection provided some rotational restraint at the connection, so the camber didn’t come out and those damn studs were actually sticking out of the top of concrete at midspan – so I am not going to camber that much again!
  • I don’t trust the code deflection criteria and invent my own
  • what is my min percent composite action or max stud per foot or min length to use camber, etc
  • when is it a good idea to just optimize a beam for efficiency (code stuff), if I was designing the smallest possible beam it could have 3″ of camber and 4 studs per foot!
  • should I use ASD or LRFD, does it matter, when does it matter and how or should I stick to my old ASD 89 green book and say to hell with 2005 and omega factors
  • what should I use as a max live load deflection when supporting CMU or Brick walls, L/600 or L/900 or ?
  • why am I designing steel in the first place, should we consider concrete or wood or ??? for this beam
  • am I comfortable assuming this beam is braced to 1.5″ metal deck (parallel) or and should I check lateral torsion bucking with the wet concrete loads
  • should I assume that there is a true pin at the shear connection, or is there some rotational stiffness there. If so can I get relief from not meeting the code live load deflection criteria – sure why not.
  • can I assume the beam is fully braced if the top flange if supporting a wood framed floor with joist hangers and how do I evaluate whether a joist hanger can brace my steel beam effectively
  • why did I just check shear yielding when shear yielding never ever controls the shear strength of the beam, what a waste of time but this was something I learned in school, so I will procede to check rupture, etc ,etc
  • do I need to check block shear of a beam web when the cope is less wide than the dist to the bolt line
  • what should I be optimizing when design a beam and how do I prioritize efficiency, economy, connectivity, constructability, deflection camber and stud count
  •  etc etc

I can go on this forever!  The code says nothing about these questions.  So my point is – even in the design of a simple beam, the code plays a small role. If we extend that to the infinite number of problems we face than we will see the code is of importance on a small fraction of problems.  So again…the code helps a little but for the most part we are on our own.  That is a good thing.

What We See Depends Mainly on What We Look For

 What we see depends mainly on what we look for.  [John Lubbock, British banker, politician, naturalist and archaeologist]

If this is the case, what precedes this?   What should we look for?   This is why experience is so important in engineering.  Determining what to look for is about prioritizing things we should look for and things we should ignore.

To know what to ask is already to know half. [Durant summarizing Aristotle]

Since engineering, like art, is the conscious use of skill and creative imagination, in addition to the ability to sift through many parameters, the only way to create a solution is to ignore things we can ignore and spent time on the things we need to spend time on.   The only way to do this is to actively look for things that matter on our projects.