David D. Clark is one of the key scientists that helped build and reshape the internet almost since its very inception (the first nodes of ARPAnet became functional in 1969). His book is a powerful reflection on the way the network has evolved from its very start in the early 1960s till today. The focus of Clark’s book is not on the internet as we use it 24/7 or on the countless applications that continue to be added to the system, but on the very heart of the internet, namely the way its fundamental architecture is designed to become what it was meant to be and what it actually still is today: an information packet transport system using specific electronic protocols to transfer information from a sender to a receiver (the analogy with the postal system is not false, in spite of all the technological differences between the two systems). Clark stresses how wonderfully robust this fundamental structure has proven to be, for after so many years and often radical reorientations all essential aspects, structures and functions of the first internet are still in place. Moreover today there does not seem to exist a strong demand for a radically different internet. Despite all the issues that the dizzying expansion of the network has inevitably laid bare and the many problems we are now all perfectly aware of, the basic design is still considered, for good or bad reasons, “good enough” to be continued.

Designing an Internet –“an” Internet, not “the” Internet–“ is thus an attempt to identify, understand, analyze and if possible remediate, albeit in very speculative ways, the progressively disclosed problems of the fundamental design (for instance problems with “naming” the packets that are transferred over the system). Clark does so by emphasizing the advantages of a minimalist design, a design philosophy that sticks to the “better done than perfect” principle, while also believing that good design should only care about the fundamental aspects of the system rather than trying to implement new or other functionalities. Such minimalist approach does not only create more robust systems, it is also imperative when one wants to cope with problems that the first generations of internet engineers did not, that is: could not, take into account, such as security, sustainability, social demands and, yes, profit. By the way, according to Clark, one of the majors reasons why the internet proves so curiously stable is the fact that the private sector, which came to take over from the public sector in the 1980s, does not have sufficient incentives to massively invest in the fundamental design of the system (built with public many in the years before). Technology is risky business, and the risks are lower at the level of what comes on top of the fundamental architecture. In other words, private enterprises are more interested in applications than in the foundational layer of packet sending structures.

Clark is a wise man. It suffices to notice his sense of humor. He is also a brilliant scientist, as shown by his capacity to make the internet understandable to lay persons, who are no less than his colleagues and other specialists in the field the intended audience of this book. But he is also a great writer, not only because of his stimulating didactic style, but also because of his perfect sense of timely delivery: Nothing comes too early, nothing is said with delay, the author does not shy away from useful repetitions, just as he always uses the exact number of words and sentences to express his ideas, never too little or not enough, whereas the words he uses are always the right ones, with helpful indexes, definitions, and acronyms at the end of the book. In short, at any page of the book the readers has the impression that she keeps a good overview of the full argument, even if certain technical details may not always be very easy to grasp.

It is the mix of great wisdom, visionary thinking, and exemplary writing that makes Designing an Internet a thrilling experience. Here are some lessons I would personally like to draw from this book.

First, this is a book that succeeds in radically going beyond the old two cultures debate, not by proposing a hybrid merger of alpha and beta sciences, but by the deep attention a “hard” scientist gives to “soft” social, cultural, and historical factors, such as for instance the observation that freedom of information, which we tend to take for granted as a universal and self-evident human right, is not always a top priority in certain traditions, which leads Clark to fundamental questions on how to make sure that something like the internet can function in a world that is divided by irreducible political and ideological tensions. As one easily images, these questions are harder to answer than metaphysical questions on who is right and who is wrong when it comes down to freedom with capital F.

Second, this is also a book that displays the fundamental modesty of scientists, a social group often discarded, and not only by those who do not really understand what scientists are actually doing, as valets of capitalism, indifferent to the human and social impact of their work as well as incapable of looking through the golden walls of their laboratories. Clark’s book gives a completely different view of the scientist’s work, not by proclaiming in either abstract or purely financial terms the benefits of this work but by permanently looking back on the job done and looking forward to the job to be done. Clark tries to understand why internet engineers did not always make the right decisions (or in certain cases: did not make any decision at all), while asking no less whether we should really think that the decisions that are currently under scrutiny are the good ones. This very open attitude, which has nothing to do with politically correct self-flagellation, makes Designing an Internet a deeply human book and its reading, a very sobering experience.

Third, this is also a book on “how to write”, and I strongly recommend it in place of all the creative writing manuals of the whole world. During all 420 pages of the book, Clark really shows how one should write, not only on this kind of very difficult topics, but in general, on any topic whatsoever. Not by telling, but by doing and thus showing: a simple, plain style, perfectly fit to what readers need, very lively, but never flashy or ostentatious, eager to discuss hard matters with technical details if necessary but always with an open eye and ear to ordinary language and daily conversation as well as to the diversity of human nature, as suggested by the repeated invitation to stop reading the book and continue with some science.