John of Salisbury - Collected Quotes

"A wide knowledge of probabilities constitutes a master key whose use is universal." (John of Salisbury, "Metalogicon", 1159)

"All knowledge or cognition possessed by creatures is limited. Infinite knowledge belongs solely to God, because of His infinite nature." (John of Salisbury, "Metalogicon", 1159)

"All things have a way of adding up together, so that one will become more proficient in any proposed branch of learning to the extent that he has mastered neighboring and related departments of knowledge." (John of Salisbury, "Metalogicon", 1159)

"Among all the liberal arts, the first is logic, and specifically that part of logic which gives initial instruction about words. [...] the word 'logic' has a broad meaning, and is not restricted exclusively to the science of argumentative reasoning. [It includes] Grammar [which] is 'the science of speaking and writing correctly - the starting point of all liberal studies'." (John of Salisbury, "Metalogicon", 1159)

"Among the various branches of philosophy, logic has two prerogatives: it has both the honor of coming first and the distinction of serving as an efficacious instrument throughout the whole body [of philosophy]. Natural and moral philosophers can construct their principles only by the forms of proof supplied by logicians. Also, in order to define and divide correctly, they must borrow and employ the art of the logicians. And if, perchance, they succeed in this without logic, their success is due to luck, rather than to science. Logic is 'rational' [philosophy], and we may readily see from the very name, what progress in philosophy can be expected from one who [since he lacks logic] lacks reason." (John of Salisbury, "Metalogicon", 1159)

"Art is a system that reason has devised in order to expedite, by its own short cut, our ability to do things within our natural capabilities. Reason neither provides nor professes to provide the accomplishment of the impossible. Rather, it substitutes for the spendthrift and roundabout ways of nature a concise, direct method of doing things that are possible." (John of Salisbury, "Metalogicon", 1159)

"But every art has its own special methods, which we may figuratively characterize as its 'approaches' or 'keys'. Seeking is a necessary preliminary to finding, and one who cannot endure the hardship of inquiry cannot expect to harvest the fruit of knowledge. Demonstrative logic, however, seeks methods [of proof] involving necessity, and arguments which establish the essential identification of terms that cannot be thrust asunder. Only that which cannot possibly be otherwise is necessary." (John of Salisbury, "Metalogicon", 1159)

"Following in the path of the foregoing, Mathematics rides [proudly] along on the four-wheel chariot of its Quadrivium, intermingling its fascinating demonstration in manifold variety." (John of Salisbury, "Metalogicon", 1159)

"For in such a case, the teacher has a double job: the first to erase the [effects of] previous faulty instruction, the second to give the student true and correct training." (John of Salisbury, "Metalogicon", 1159)

"If one, with the scientist, studies the works of nature, which are made up of elements or matter and form, his reasoning is dependent on the data provided by sense-experience. And if one, with the mathematician, abstracts figures or calculates numerically, he must, in order to gain assent, accurately adduce many examples of both differentiated plurality and quantitative extension. The like holds true of the philosopher, whose domain is [abstract] reasoning, and who is the client of both the scientist and the mathematician. For the philosopher, too, begins with those things which are based on the evidence of the senses and contribute to the knowledge of immaterial intelligibles." (John of Salisbury, "Metalogicon", 1159)

"Imagination is accordingly the first activity [movement] of the soul after it is subjected to external stimulation. Imagination  either formulates second judgment, or brings back first judgment by recollection." (John of Salisbury, "Metalogicon", 1159)

"In creation, on the other hand, truth is one thing, reason another. For in creation, truth is an image of the divinity, which is sought and found by reason in created things. Reason is a virtue or activity of the mind, whose object is to discern truth. Truth, like reason, does not have any contrary, and this for the same cause that was given and explained above in regard to reason." (John of Salisbury, "Metalogicon", 1159)

"In our acquisition of [scientific] knowledge, investigation is the first step, and comes before comprehension, analysis, and retention. Innate ability, although it proceeds from nature, is fostered by study and exercise. What is difficult when we first try it, becomes easier after assiduous practice, and once the rules for doing it are mastered, very easy, unless languor creeps in, through lapse of use or carelessness, and impedes our efficiency. This, in short, is how all the arts have originated: Nature, the first fundamental, begets the habit and practice of study, which proceeds to provide an art, and the latter, in turn, finally furnishes the faculty whereof we speak. Natural ability is accordingly effective. So, too, is exercise. And memory likewise, is effective, when employed by the two aforesaid. With the help of the foregoing, reason waxes strong, and produces the arts, which are proportionate to [man’s] natural talents." (John of Salisbury, "Metalogicon", 1159)

"Indeed, God made matter from nothing, while form, likewise simultaneously created from nothing, is united with this matter, in such a way that, just as the privilege of determination is granted to the form, so that of existence is accorded to the matter. Thus, in a way, the form exists through the matter, while conversely the matter is determined by the form. Neither does the form exist of itself, nor would the matter be determinate without the form. Chaos would reign, or rather the sensible world would come to an end, if nature did not compose the figures of things by means of forms." (John of Salisbury, "Metalogicon", 1159)

"[Intuitive] Understanding is consequent upon deliberation, and firmly embraces the better part. For [intuitive] understanding concerns itself with divine truths, and the relish, love, and observance of the latter constitutes true wisdom. Rather than being the [mere] product of nature, these successive steps are the result of grace. The latter, according to its own free determination, derives the various rivulets of the sciences and wisdom from the fountainhead of sense perception. Grace reveals hidden divine truths by means of those things which have been made, and by that unity which belongs to love, communicates what it has made manifest, thus uniting man to God." (John of Salisbury, "Metalogicon", 1159)

"It is true that mathematics, which deals theoretically with abstractions, and in its subtle analysis separates things that are united in nature, treats matter and form apart from one another, so that the nature of what is composite may be more accurately and definitely understood. Still, the one cannot exist apart from the other, as [in this case] either matter would be without form, or form would lack a subject and hence be ineffective." (John of Salisbury, "Metalogicon", 1159)

"Of all things the most desirable is wisdom, whose fruit consists in the love of what is good and the practice of virtue. Consequently the human mind must apply itself to the quest of wisdom, and thoroughly study and investigate questions in order to formulate clear and sound judgments concerning each." (John of Salisbury, "Metalogicon", 1159)

"Physics inquires whether the world is eternal, or perpetual, or had a beginning and will have an end in time, or whether none of these alternatives is accurate." (John of Salisbury, "Metalogicon", 1159)

"Reason, on its part, is that power of the soul which examines and investigates things that make an impression on the senses or intellect. A dependable judge of better things, reason has, after estimating similarities and differences, finally established art, to be, as it were, a circumscribed science of unlimited things." (John of Salisbury, "Metalogicon", 1159)

"That [logic] which makes a pretext of being dialectical and demonstrative [logic] with a flourish of hollow imitation, and strives more to acquire the [external] semblance than the [true] virtue of wisdom, is known as 'sophistry'. [...] For sophistry affects the appearance of wisdom, rather than its reality, while the sophist bubbles over with simulated, rather than actual wisdom. Sophistry disguises itself as all the disciplines, and masked, now as one, now as another of the various branches of knowledge, lays its traps for everyone, and catches the unwary." (John of Salisbury, "Metalogicon", 1159)

"The employment of tropes, just as the use of schemata, is the exclusive privilege of the very learned. The rules governing tropes are also very strict, so that the latitude in which they may be used is definitely limited. For the rules teach that we may not extend figures. One who is studiously imitating the authors by using metaphors and figures, must take care to avoid crude figures that are hard to interpret. What is primarily desirable in language is lucid clarity and easy comprehensibility. Therefore schemata should be used only out of necessity or for ornamentation. Speech was invented as a means of communicating mental concepts; and figures [of speech] are admitted so far as they compensate by their utility for whatever they lack in conformity to the [rules of the grammatical] art." (John of Salisbury, "Metalogicon", 1159)

"The method of demonstration is therefore generally feeble and ineffective with regard to facts of nature (I refer to corporeal and changeable things). But it quickly recovers its strength when applied to the field of mathematics. For whatever it concludes in regard to such things as numbers, proportions and figures is indubitably true, and cannot be otherwise. One who wishes to become a master of the science of demonstration should first obtain a good grasp of probabilities. Whereas the principles of demonstrative logic are necessary; those of dialectic are probable." (John of Salisbury, "Metalogicon", 1159)

"There are also schemata, which we may translate as figures in wording or sense, and which comprise various forms of diction used to embellish speech. Barbarisms and metaplasms occur in single words; solecisms and schemata, not in individual words, but in the joining of a number of words." (John of Salisbury, "Metalogicon", 1159)

"Things that are necessary and probable should be distinguished from their opposites, and also from each other. The meanings of words should be carefully determined, since a person who has this knowledge can see that a single statement may readily imply several propositions, whereas, on the other hand, several statements may be reduced to a single proposition. Extreme care should be observed in establishing or eliminating universal, for it is quite evident that these constitute both the greatest secrets of success and the chief obstacles to progress." (John of Salisbury, "Metalogicon", 1159)

"Thus when love of reason, which concerns earthly things, ascends with prudence to the hidden secrets of eternal and divine truths, it becomes transformed into wisdom, which is in a way exempt from mortal limitations." (John of Salisbury, "Metalogicon", 1159)

"Truth is both the light of the mind and the subject matter of reason." (John of Salisbury, "Metalogicon", 1159)