Smith begins his discussion of the need for an interdisciplinary approach to liberty by noting some hazards of academic specialization.

George H. Smith was formerly Senior Research Fellow for the Institute for Humane Studies, a lecturer on American History for Cato Summer Seminars, and Executive Editor of Knowledge Products. Smith’s fourth and most recent book, The System of Liberty, was published by Cambridge University Press in 2013.

The eighteenth‐​century philosopher Immanuel Kant, who had much to do with infusing the spirit of liberal individualism into European thought, wrote a famous essay, “What is Enlightenment?” in which he answered his own question as follows:

Enlightenment is man’s emergence from his self‐​incurred immaturity. Immaturity is the inability to use one’s own understanding without the guidance of another. This immaturity is self‐​incurred if its cause is not lack of understanding, but lack of resolution and courage to use it without the guidance of another. The motto of enlightenment is therefore:…Have courage to use your own understanding.

Many people, according to Kant, depend on various experts and authorities to tell them what they should believe and how they should behave. Enlightenment, or intellectual autonomy, consists of breaking free from this dependency and learning to think for oneself.

For enlightenment of this kind, all that is needed is freedom. And the freedom in question is the most innocuous form of all–freedom to make public use of one’s reason in all matters. But I hear on all sides the cry: Don’t argue! The officer says: Don’t argue, get on parade. The tax‐​officials, Don’t argue, pay! The clergyman, Don’t argue, believe!.…The public use of man’s reason must always be free, and it alone can bring about enlightenment among men.

This call for independent thinking did not originate during the Enlightenment; it was part and parcel of modern philosophy, which is commonly traced to the early 1600s, especially to the writings of Francis Bacon (1561–1626) and Rene Descartes (1596–1650). Both men, working from different philosophic perspectives, expressed contempt for the academics of their day, those scholastics (or “schoolmen”) who were hidebound defenders of orthodox beliefs in philosophy, theology and science. By fragmenting knowledge into specialized fields, academics had established themselves as experts and authorities–as arbiters of truth within their privileged domains.

According to Bacon, these intellectual “dictators” exhibited the characteristic signs of a “falsified science,” including a “novelty and strangeness” of technical terms that made their “degenerate learning” seem profound and esoteric. Another sign was the “strictness of positions” that served to exclude criticism and dissenting viewpoints.

To combat the deleterious effects of academic specialization, Bacon and Descartes argued that philosophers should integrate the knowledge acquired in different sciences by using a comprehensive methodology. Bacon called for a method that was essentially inductive, whereas Descartes favored a kind of deductive reasoning from clear and distinct ideas. Both philosophers, however, insisted that scientific knowledge is not the prerogative of a minority; and both believed that knowledge, when organized and integrated into a comprehensible system, could be used for the benefit of humankind.

In Rules for the Direction of the Mind, Descartes argued that academic specialization rested on an erroneous comparison between the arts and the sciences. (These terms had a broader meaning in the seventeenth century than they do now. “Science” referred to the systematic pursuit of knowledge, whereas “art” referred to the practical application of knowledge, as we find in technology and manual skills.) According to Descartes, specialization, which results from the division of labor, is necessary in the arts. It is much easier for a man to learn one skill rather than many; we do not expect, for example, the same person to become proficient in both farming and harp playing. And because of this need for specialization in the arts, it was commonly believed that there exists a similar need for specialization in the sciences. But Descartes disagreed:

[Men] have held the same to be true of the sciences also, and distinguishing them from one another according to their subject matter, they have imagined that they ought to be studied separately, each in isolation from all the rest. But this is certainly wrong. For since the sciences taken all together are identical with human wisdom, which always remains one and the same, however applied to different subjects, and suffers no more differentiation proceeding from them than the light of the sun experiences from the variety of the things which it illumines, there is no need for minds to be confined at all within limits; for neither does the knowing of one truth have an effect like that of the acquisition of one art and prevent us from finding out another; it rather aids us to do so.

Knowledge is useful insofar as it contributes to the wisdom of mankind. But this general purpose is lost sight of when we confine ourselves to a special investigation and make no attempt to integrate the knowledge from one discipline with the knowledge from other disciplines.

[W]e must believe that all the sciences are so inter‐​connected, that it is much easier to study them all together than to isolate one from all the others. If, therefore, anyone wishes to search out the truth of things in serious earnest, he ought not to select one special science; for all the sciences are conjoined with each other and interdependent: he ought rather to think how to increase the natural light of reason, not for the purpose of resolving this or that difficulty of scholastic type, but in order that his understanding may light his will to its proper choice in all the contingencies of life. In a short time he will see with amazement that he has made much more progress than those who are eager about particular ends, and that he has not only obtained all that they desire, but even higher results than fall within his expectation.

As a key to understanding the special sciences, Descartes (as noted earlier) proposed a method of deductive reasoning, modeled after geometry, from clear and distinct ideas. Francis Bacon agreed with Descartes on the need for a unified method of reasoning, but he proposed an inductive method instead, in which principles are based on the careful observation and classification of particular facts. Thus Bacon became a founding father of modern empiricism, while Descartes laid the foundation for the tradition known as rationalism.

Empiricism found many advocates among British philosophers, such as Thomas Hobbes, John Locke and David Hume; whereas rationalism appealed more to Continental philosophers, such as Benedict Spinoza and Gottfried Leibnitz. Despite their differences, however, the major representatives of both schools had at least two things in common. First, all were deeply interested in the scientific discoveries of their day; and, second, all were convinced that philosophy has a vital role to play in the interpretation and integration of scientific knowledge. Indeed, the intense interest of modern philosophers in epistemology, or the theory of knowledge, was largely inspired by the remarkable achievements in mathematics, physics, astronomy, and other disciplines. With the tremendous outpouring of this specialized knowledge, philosophy was widely regarded as the grand integrative discipline–the repository of fundamental principles that would enable us to retain an overall perspective, to apply knowledge gained in one science to the other sciences, and to utilize scientific knowledge for the betterment of humankind.

Today we are frequently told that this interdisciplinary ideal, which seeks to integrate various fields of knowledge into an integrated system, is impossible to achieve and therefore foolish even to attempt. We are told that our knowledge has expanded so dramatically and has become so technical and specialized that no one person, however brilliant, can possibly acquire competence in more than a single, narrowly circumscribed cognitive discipline. College students are warned that they must specialize if they wish to advance their careers; they must publish primarily in professional journals that are read, if they are read at all, only by other professionals. Academic specialization, not the interdisciplinary ideal of an earlier age, is the order of the day in the modern university.

The net result of this academic imperative has been, in effect, the fragmentation of knowledge into airtight compartments, each safely insulated from the criticisms of those not officially qualified to pronounce judgment. Should a nonspecialist trespass into the sovereign domain of a credentialed specialist, he will be ridiculed and summarily dismissed as a rank amateur or (as academics are fond of saying) as a “mere dilettante.”

This hyper‐​specialization has disastrous implications for the study of liberty, which is, and must be, an interdisciplinary enterprise. This is scarcely a new observation. Adam Smith, Herbert Spencer, John Stuart Mill, and other prominent classical liberals made similar points.

In the Wealth of Nations, Smith said of the university system that it was one of the last strongholds of the medieval guild and its special privileges. The undergraduate, like the apprentice, undergoes four years of training. Then the graduate student, like the journeyman, undergoes three more, until he graduates into the ranks of the master-craftsman–one who is officially certified to practice and teach the mysteries of his craft. Smith noted that this system was more advantageous to professors than to students, and he suggested, somewhat impolitely, that it was maintained for precisely that reason.

Herbert Spencer, an interdisciplinary intellectual of great breadth and a product of home schooling who possessed no academic credentials whatever, maintained that the main defenders of individual freedom were found outside the university system. The greatest blunders in legislation were committed by men with “university‐​degrees,” whereas the majority of freedom’s defenders “have not been graduates of universities.” Spencer continued: “In this all‐​important direction, right legislation was urged by men deficient in the so‐​called best‐​education; and was resisted by the great majority of men who had received this so‐​called education.”

Most universities did not impart the interdisciplinary “knowledge of Social Science” that is essential for a “true theory of government.” As for those who deride the need for theory in political affairs, Spencer argued that this attitude will inflict severe damage on the cause of freedom. Without a general understanding of social and economic theories, which explain the harmful, if often remote and indirect, consequences of political intervention, legislators will continue to justify each new law and regulation with ad‐​hoc and short‐​term arguments. Spencer concluded: “These evils can be prevented, only by establishing in the public mind a profound conviction that there are certain comparatively narrow limits to the function of the state.”

John Stuart Mill, who is recognized by friend and foe alike as one of the greatest minds of the nineteenth century, was also a product of home schooling. And, like Spencer and other classical liberals, Mill despaired of the narrow specialization that was overtaking education. In his Inaugural Address at Saint Andrews (1867), Mill had this to say:

If the inexorable conditions of human life make it useless for one man to attempt to know more than one thing, what is to become of the human intellect as facts accumulate? In every generation, and now more rapidly than ever, the things which it is necessary that somebody should know are more and more multiplied. Every department of knowledge becomes so loaded with details, that one who endeavors to know it with minute accuracy, must confine himself to a smaller and smaller portion of the whole extent: every science and art must be cut up into subdivisions, until each man’s portion, the district which he thoroughly knows, bears about the same ratio to the whole range of useful knowledge that the art of putting on a pin’s head does to the field of human industry. Now, if in order to know that little completely, it is necessary to remain wholly ignorant of all the rest, what will soon be the worth of a man, for any human purpose except his own infinitesimal fraction of human wants and requirements? His state will be even worse than that of simple ignorance. Experience proves that there is no one study or pursuit, which, practised to the exclusion of all others, does not narrow and pervert the mind; breeding in it a class of prejudices special to that pursuit, besides a general prejudice, common to all narrow specialities, against large views, from an incapacity to take in and appreciate the grounds of them.

Despite this warning, Mill sounded an optimistic note. The classical notion of a liberal, interdisciplinary education was still possible, despite the rapid expansion of knowledge. Education should not confine itself to one field, piling fact upon fact while ignoring broader principles and the contributions of other disciplines. Rather, we should strive “to combine a minute knowledge of one or a few things with a general knowledge of many things.” This general, or interdisciplinary, knowledge provides a basic framework in which the more specialized knowledge from various fields can be understood and evaluated. Such interdisciplinary knowledge is crucial in matters involving government and public policy.

Government and civil society are the most complicated of all subjects accessible to the human mind; and he who would deal competently with them as a thinker, and not as a blind follower of a party, requires not only a general knowledge of the leading facts of life, both moral and material, but an understanding exercised and disciplined in the principles and rules of sound thinking, up to a point which neither the experience of life, nor any one science or branch of knowledge, affords.

It must be stressed that none of the previously cited writers objected to specialization as such, either in the human or in the natural sciences. All were aware that cognitive specialization is both necessary and desirable for the progress of knowledge. But they warned against the compartmentalizing of knowledge that sometimes accompanies specialization, because this tends to generate a class of intellectuals and academics who function, to use Bacon’s term, like dictators in their respective sciences. In the same way that members of medieval guilds spoke of the “mysteries” of their crafts–referring to a kind of knowledge that was accessible only to those who had undergone the required training–so academics sometimes present their specialized knowledge as immune to critical examination by nonspecialists who have not been properly initiated into the mysteries of their science.

In Philosophy as Social Expression (University of Chicago Press, 1974), Albert William Levi noted that “from the birth of Francis Bacon in 1561 to the death of David Hume in 1776–that is, for two hundred years–not one first‐​rate philosophic mind in Europe is permanently associated with a university.” Those two centuries, which saw the rise of the independent intellectual, were crucial to the development of libertarian ideas. This overlap, I humbly suggest, was not mere coincidence.