Engineers are not superhuman. They make mistakes in their assumptions, in their calculations, in their conclusions. That they make mistakes is forgivable; that they catch them is imperative. Thus it is the essence of modern engineering not only to be able to check one's own work but also to have one's work checked and to be able to check the work of others.

Engineering is achieving function while avoiding failure.

The most amazing achievement of the computer software industry is its continuing cancellation of the steady and staggering gains made by the computer hardware industry.

A failed structure provides a counterexample to a hypothesis and shows us incontrovertibly what cannot be done, while a structure that stands without incident often conceals whatever lessons or caveats it might hold for the next generation of engineers.

All conventional wisdom has an element of truth to it, but good design requires more than an element of truth - it requires an ensemble of correct assumptions and valid calculations.

Design is nothing if not decision making.

Whether or not science can be applied to that mental construct [i.e. the designed entity] is a matter of availability. If there is body of scientific knowledge that can be applied, then it would be foolish not to exploit it. However, if there is none, it does not mean that the thing cannot be designed, made, and used safely.