Niccolò Machiavelli, the great Italian thinker of the late Renaissance, thought the matter so important that he had to repeat it twice in his writings, slightly differently, to make sure that none of his readers missed it. ^1,2

"So in all human affairs one notices, if one examines them closely, that it is impossible to remove one inconvenience without another emerging."

"In human affairs there is, in addition to others, this difficulty: When one wants to bring things up to perfection, one always finds that, bound up with what is good, there is some evil... and it would seem impossible to have one without the other."

Throughout human experience, Machiavelli's keen observation has proven to be amply correct. There is no way to improve something without producing a side effect, which acts to offset the gain with a perceptible associated loss. Nature's hand appears very clearly here. No matter how many times we repeat it, the gain and loss dichotomy appears, if one is willing to carefully look at all the causes and effects.

To illustrate the matter further, using a case that many people may be familiar with, we focus here on hydraulic engineering, with an example from Machiavelli's observation. The construction of dams, an activity to which contemporary societies have tenaciously dedicated themselves in the last 120 years, has produced good and bad effects.³ Good, because water has been conveniently stored for use when and where it was necessary; bad, because the dam invariably causes negative environmental impacts that did not exist before its construction. ⁴

And history repeats itself everywhere throughout time, confirming Machiavelli's observation. There seems to be no way out of this intensely human predicament.

¹ Maquiavelo, N. 1517. Discourses on Livy.

² Remembering Machavelli. http://ponce.sdsu.edu/mach/index.html.

³ There are more than 90 000 dams in the United States [Google, cited on May, 2020].

⁴ Ponce, V. M., and A. V. Shetty. 2002. Environmental impact of dams.