The first goes by the name of eclecticism, by which is meant the approach of those who, in research, teaching and argumentation, even in theology, tend to use individual ideas drawn from different philosophies, without concern for their internal coherence, their place within a system or their historical context. They therefore run the risk of being unable to distinguish the part of truth of a given doctrine from elements of it which may be erroneous or ill-suited to the task at hand.I do not understand this completely, which is why I think it is so interesting, but I think the operative concern here is:
without concern for their internal coherence, their place within a system or their historical context
It reminded me a bit of what Pope Pius XI says in Divini Illius Magistri in regard to education:
In such a school moreover, the study of the vernacular and of classical literature will do no damage to moral virtue. There the Christian teacher will imitate the bee, which takes the choicest part of the flower and leaves the rest, as St. Basil teaches in his discourse to youths on the study of the classics.Nor will this necessary caution, suggested also by the pagan Quintilian, in any way hinder the Christian teacher from gathering and turning to profit, whatever there is of real worth in the systems and methods of our modern times, mindful of the Apostle's advice: "Prove all things: hold fast that which is good."
Hence in accepting the new, he will not hastily abandon the old, which the experience of centuries has found expedient and profitable. This is particularly true in the teaching of Latin, which in our days is falling more and more into disuse, because of the unreasonable rejection of methods so successfully used by that sane humanism, whose highest development was reached in the schools of the Church. These noble traditions of the past require that the youth committed to Catholic schools be fully instructed in the letters and sciences in accordance with the exigencies of the times. They also demand that the doctrine imparted be deep and solid, especially in sound philosophy, avoiding the muddled superficiality of those "who perhaps would have found the necessary, had they not gone in search of the superfluous."
Neither of the encyclicals are opposed to respecting and understanding and adopting what is good in cultures and philosophies that are separate from a Christian tradition -- but both caution against an uncritical "cafeteria" approach that does not weigh and evaluate. ... that is, as Pope Pius XI says, does not measure "worth" which inevitably is a comparative.
There is more about the philosophy of eclecticism at the Catholic encyclopedia.
Eclecticism errs when it substitutes for personal reflection as the primary source of philosophy a mere fusion of systems, or the history of philosophy for philosophy proper. Eclecticism does not furnish us with the ultimate principles of philosophy or the criterion of certitude. We cannot say that philosophy has reached the highest degree of precision either in its solution or in its presentation of every problem; nor that it knows all that can be known about nature, man, or God. But even if this were the case, the principles of Eclecticism cannot provide us with a firm, complete, and true system of philosophy. ......The eclectic must first separate error from truth before building into a system the results of his discrimination. But this is possible only on the condition of passing a judgment upon each of these systems and therefore of having, quite apart from history, some rational principle as an ultimate criterion. In a word, Eclecticism, considered as a study of the opinions and theories of others in order to find in them some help and enlightenment, has its place in philosophy; it is a part of philosophic method; but as a doctrine it is altogether inadequate.
Note that this is talking about philosophy which is related to education but not identical to it. Still, education does depend upon philosophy since it is intrinsically concerned with what people are capable of, where and how knowledge comes about, and other things of that sort. I consider myself an "eclectic" homeschooler in a way, and I don't think this is a problem IF, as the article cautions, the bits and pieces are evaluated according to general principles.
Charlotte Mason was one educator who often emphasized that any educational practice must be regarded according to how it falls in with true ideas about the human person. It was particularly important in her time when the formal science of psychology was just gaining ground and there were a lot of false ideas in the air. But some of them are still with us, and you can see that education is even less generally successful than it was in her day.
In Economics in One Lesson, Hazlitt notes how difficult it is to caution about secondary consequences. It is easy to see that Program A or Intervention B has various good results. It is not so easy to see that A and B might prevent C and D -- perhaps even better things -- from ever coming into being. Possibly the same thing applies in educational matters. The "cafeteria" approach in education can work this way, which is one of the main criticisms of the modern American supermarket-style universities. You can get your academic kicks in all sorts of ways, without ever approaching much more closely to the center of things. It is not that a variety is bad. It is that it can displace something better.
The Ignatian Ratio Studiorum recommended a hierarchy, which has been a useful concept for me. Some subjects are simply closer to the heart of things than others. The Ratio puts the emphasis on the development of language -- competency in comprehension and expression. In the context of a formative education, this competency will not be isolated technical skill but will be closely related to development of virtue. That is, the goal of education is to "think, speak and act well." So the content of the literary education will be excellent, because its purpose is formative. By hearing, reading, thinking upon and expressing good things, one learns to understand and participate in the good. This is an integrated purpose, and is a useful standard by which to evaluate whether or not a method or course is beneficial in the curriculum.