It has to be seen whether there are limitations to research and teaching and what these limitations are. All things in this world may be considered from a triple point of view: from the logical, the physical, and the ethical. Applied to science we discover limitations in all three.
Logical
Logically science is limited by truth, which belongs to its very essence. Knowledge of things cannot be had from their causes, unless the knowledge be true. False knowledge cannot be derived from the causes of things; it has its origin in some spurious source. Should science ever have to choose between truth and freedom (a choice not at all imaginary), it must under all circumstances decide for truth, under penalty of self-annihilation. As long as the case is thus put theoretically, there is no difference of opinion. Yet in practice, it is almost hopeless to reconcile conflicting sentiments. When, in 1901, a vacant chair at the University of Strasburg was to be filled by a Catholic historian, Mommsen published a protest, in which he exclaimed: "A sense of degradation is pervading German university circles". On that occasion he coined the shibboleth "voraussetzungslos", and claimed that scientific research must be "without presuppositions". The same cry was raised by Harnack (1908) when he demanded "unbounded freedom for research and knowledge". The demand was formulated a little more precisely by the congress of academicians in Jena (1908). Their claim for science was "freedom from every view foreign to scientific methods".
In the latter formula the claim has a legitimate meaning, viz., that unscientific views should not influence the results of science. In the meaning of Mommsen and Harnack, however, the claim is illogical in a double sense. First, there can be no "science without presuppositions". Every scientist must accept certain truths dictated by sound reason, among others, the truth of his own existence and of a world outside of himself; next, that he can recognize the external world through the senses, that a reasoning power is given to him for understanding the impressions received, and a will power free from physical constraint. As a philosopher, he reflects upon these truths and explains them on scientific methods, but will never prove all of them without involving himself in vicious circles. Whatever science he chooses he has to build it upon the natural or philosophical presuppositions on which his life as man rests. The fact is that every positive science borrows from philosophy a number of established principles.
So much for the general premises. They alone would show how illogical is the claim for "science without presuppositions". But this is not all. Each science has its own particular presuppositions or axioms, distinct from its own conclusions, just as every building has its foundation, distinct from its walls and roof. Nay, the various branches of any special science have all their own proper presuppositions. Euclid's geometry is built upon three kinds of presuppositions. He calls them definitions, postulates, and common notions. The latter were called axioms by Proclus. To show the difference between hypothesis and result no better example could be chosen than Euclid's fifth postulate of the first book. The postulate says: "When two straight lines are intersected by a third so as to make the inner adjacent angles on one side less than two right angles, the two lines, indefinitely prolonged, will intersect on the side of those lesser angles." By a mistake of Proclus (fifth century) the postulate was changed into a proposition. Innumerable attempts at proving the supposed proposition were made, until the error was recognized, only a century ago. The fifth postulate, or axiom of parallels as it is often called, proved to be a real hypothesis, distinct from all the other presuppositions. Non-euclidian geometries have been constructed by a simple change of the fifth postulate. All this shows that there is no geometry without presuppositions. And similarly, there is no algebra without presuppositions. Law starts from the existence of families and from their natural tendency towards association for common welfare. Medicine takes the human body as a living organism, subject to derangement, and the existence of remedies, before it constructs its science. History supposes human testimony to be, under certain conditions, a reliable source of knowledge, before it begins its researches. Linguistic sciences, likewise, take it or granted that human languages are not constructed arbitrarily but evolved logically from a variety of circumstances. Theology takes from philosophy a number of truths, such as the existence of God, the possibility of miracles, and others. In fact, one science borrows its presuppositions from the results of other sciences, a division of labour which is necessitated by the limitations of everything human. Hence, the cry for "science without presuppositions" is doubly illogical, unless by presupposition is meant an hypothesis that can be proved to be false or foreign to the particular science in question. The freedom of science therefore has its limitations from the point of view of logic.
Physical
From the physical point of view science requires material means. Buildings, endowments, and libraries are necessary to all branches of science, in research as well as in teaching. Medical and natural sciences require extraordinary means, such as laboratories, museums, and instruments. Material requirements have always imposed limitations upon scientific research and teaching. On the other hand, the appeals of science for freedom from the burden have been generously answered. Between the twelfth and the fourteenth centuries about forty universities were founded in Europe, partly by private initiative, partly by princes or popes, in most cases by the combined efforts of both together with the members of the university. Among the self-originating universities may be mentioned Bologna, Paris, Oxford, and Cambridge. With the help of princes, universities were erected at Palencia, Naples, Salamanca, Seville, and Siena. Of the universities founded by popes we mention only Rome, Pisa, Ferrara, Toulouse, Valladolid, Heidelberg, Cologne, and Erfurt. Most of the old universities, like Coimbra, Florence, Prague, Vienna, Cracow, Alcalá, Upsala, Louvain, Leipzig, Rostock, Tübingen, and many others, owe their origin to the combined efforts of princes and popes. The foundations consisted mainly of charters giving civil rights and authorizing scientific degrees, in most cases also of material contributions and endowments. To many of the professors' chairs, ecclesiastical benefices were applied by the popes without other obligation than that of teaching science. Naturally the founders retained a certain authority and influence over the schools. On the whole, the old universities enjoyed everywhere the same freedom which they have in England up to this day. After the Reformation the governments of continental Europe made the universities of their own territories State institutions, paying the professors as Government employees, sometimes prescribing textbooks, methods of teaching, and even doctrines. Although in the nineteenth century, governments were obliged to relax their supervision, they still keep the monopoly of establishing universities and of appointing the professors. Their influence on the progress of science is unmistakable; how far this may benefit science, need not be decided in this place. With the growing influence of the State that of the Church has been diminished, in most universities to total extinction. In the few European universities in which the faculty of Catholic theology is still allowed to exist, the supervision of the Church over her own science is almost reduced to a mere veto. The necessity of exempting the professors from the oath against the Modernistic heresy is an illustration of the case. Owing to the freedom of teaching in the United States of America there are, besides the public universities of the different states, a number of institutions founded by private endowment. In the face of the strong aid which anti-Christian and atheistic tendencies receive through the influence of universities, private endowments of schools that maintain the truth of Revelation cannot be too much recommended.
Ethical
The limitations of science from the ethical point of view are twofold. The direct action of science on ethics is readily understood; the reaction of ethics upon science is just as certain. And both action and reaction create limitations for science. The activity of man is guided by two spiritual faculties, understanding and will. From the understanding it derives light, from the will firmness. Naturally the understanding precedes the will and hence the influence of science upon ethics. This influence becomes an important factor in the welfare of the human race for the reason that it is not confined to the scientist in his own researches, but reaches the masses through the various forms of teaching by word and writing. If one is to judge aright in this matter, two general principles must be kept in view. First, ethics is more important for mankind than science. Those who believe in revelation, know that the Commandments are the criteria by which men will be judged (Matthew 25:35-46); and those who see only as far as the light of natural reason enables them to see, know from history that the happiness of peoples and nations consists rather in moral rectitude than in scientific progress. The conclusion is that if there should ever be a conflict between science and ethics, ethics should prevail. Now, there can be no such conflict except in two cases: when scientific research leads into error, and when the teaching of science, even if true, is applied against sound educational maxims. To see that these exceptions are not imaginary, one need only glance at the points of contact between science and faith, under A. All of them indicate actual conflicts. Unpedagogical teaching is sadly illustrated by the recent movement in Germany towards premature and even public instruction on sexual relations, which provoked a reaction on the part of the civil authorities.
