Crusius, Christian August: Road to certainty and reliability – Historical probability

From the general method of all research, Crusius moves on to the specific method of history. He thinks it evident that proofs in history can only use the method of probability: the links between the things in the world are so multifarious that we cannot discover the events from causes or causes from events through demonstration, and even where we could find the causes of some effects according to their essence, we could not find all circumstances of their existence. Furthermore, Crusius adds, the events of history are usually determined by the choices of free persons, while the method of demonstration can investigate only deterministic causes. Thus, he finds enough reasons to define a special historical probability, by which he means probability that helps us to distinguish justified accounts of the past from fabrications. Crusius believes that in innumerable examples of human life we have occasions of historical probability and that it often even changes into moral certainty. This means, he concludes, that we should be able to find ways to justify historical probability.

Crusius suggests several ultimate grounds of historical probability, starting with the assumption that especially fabrications, untruths and affectations reveal themselves quite easily, since it is not easy to create internally consistent stories, because fictional tales often clearly conflict with the known events of the real world and because our natural desire for truth makes it not easy for us to be fooled by deceptions. Indeed, he suggests that because of this natural desire for truth, people find credulity and deception shameful things and are therefore usually inclined to tell only such stories that they have judged to be true due to believable justifications. Thus, Crusius concludes, we should not presume that a historical account is groundless, as long as we know no particular causes that would weaken or even expressly refute the general presumption.

Of course, Crusius adds, this presumption has different degrees, depending on who is giving the account, and is especially strong in regard to public records. He notes that each person usually acts according to their status, for instance, a person who has been deceitful before is not to be trusted. Furthermore, Crusius continues, the easier it is to believe something to be possible or the more internal probability something has, the stronger is its trustworthiness. Here the particular method of historical probability points back to the general theory of probabilities: probability increases greatly, the more we have justifications and the more harmonious they are with one another. Even mere cognitive justifications might be enough for moral certainty, but links to purposes and obligations increases its strength, but no method of probability can be used further than its own justification allows, that is, when it is not weakened or even expressly refuted by opposed inferences.

Crusius notes that there are two things to evaluate with the historical justifications: firstly, the materials used as data for historical proofs, and secondly, their relation toward the suggested historical truth, the signs and grounds of which they should be. He points out that historical data can be of many types: not just history books and records, testimonies and accounts, but also memorials, coins, pictures, inscriptions, artifacts and even internal characteristics of the suggested events, that is, whether they are in themselves probable. Crusius states that first is to be investigated how certain the data are, sometimes through immediate sensations, sometimes through demonstrative grounds, but mostly through other probabilities.

Crusius reminds the reader that although we would have answered the question of the certainty of the data, we still wouldn’t have decided what the data can prove. This power of proof lies partly, he continues, in the existence and characteristic of testimonials of witnesses and in the characteristic of the things witnesses have told. Starting from the latter, Crusius explains that we should observe the possibility and the probability of things even before looking at the testimonials. Thus, he argues, we should consider the degree of possibility of the described event: for instance, are there many examples of similar things and are there clear causes that could have caused the thing at the context of that time. Furthermore, Crusius thinks, we should observe whether the suggested event has internal probability: whether it agrees with known physical and cultural circumstances or whether it contradicts them, whether the existence of such things is probable from general reasons etc. He also encourages to find any physical evidence corroborating what is told.

In addition to such internal characteristics of events, Crusius recognises testimonials as the other main source of historical proofs, whether they be testimonials of the experiences of the witnesses themselves or of someone else. He notes that we should observe whether the witness could have given a true testimonial. If they are speaking of something they have themselves supposedly experienced, do they have the required powers of sensation and attention, how much they could have actually sensed, what kind of obstacles their sensations might have had and how much time and attention the thing has required? On the other hand, Crusius adds, if we are speaking of something not directly experienced, but only inferred from something supposedly experienced by the witness (e.g. whether someone was angry), we must observe whether the witness has enough power of reasoning to do such inferences. Finally, he concludes, if the witness hasn’t personally encountered the thing they tell, the probability of their testimonials depends on the methods they have used to ascertin the truth of these tales and their capacities to use these methods.

Furthermore, Crusius continues, we should observe whether witnesses have wanted to tell the truth, that is, we should observe if for some reason it is easy to assume that they do not speak truth or whether some particular circumstances of the witnesses, such as their character, prevent this assumption. He also suggests considering whether witnesses could have deceived us, and if so, whether the deceptions have been done purposefully or due to witnesses themselves being deceived by others.

An important topic of investigation, according to Crusius, is whether testimonials agree with other testimonials – for instance, whether what the witness says here agrees with what they say elsewhere and with what other writers and historical records suggest. Even if a testimonial appears to be in contradiction with other testimonials, this seeming contradiction might be solved in other ways. If a testimonial cannot, for some reason, be compared with others, the events might still be remarkably probable for other reasons.

Crucius suggests some further rules to help in assessing historical probability of an account. Firstly, he notes, events that happen seldom or are in conflict with the natural characteristics of the causes in the world are internally improbable, thus, they require stronger historical justifications in order to become credible. Furthermore, Crusius points out, all justifications of historical probability can confirm each other reciprocally, that is, earlier events can confirm their consequences and consequences can confirm past events that caused them – we just have to know which of the two are more reliable and use them to justify the others. He also suggests that at least when dealing with events that could have been experiences, memorials of famous people provide stronger evidence for them than memorials of unknown people, while physical evidence, like coins, are generally more credible evidence than memorials.

Every testimonial has, Crusius reminds us, historical credibility, due to the presumption that people mostly speak truth, but this natural credibility can be weakened or even completely refuted by the circumstances or it can also be strengthened. Thus, historians should try to have as much information about the historical context, in order to better evaluate individual testimonies. Usually, Crusius notes, having several witnesses saying the same thing makes the account more credible, but if all the witnesses have heard the tale from the same source, their combined credibility is as great as the credibility of this source – unless, he adds, the witnesses have had more evidence, on which to base their belief in the original source. In any case, Crusius concludes, the character of the witnesses can weigh even more than their numbers.

Sometimes the credibility of testimonials is low, Crusius thinks. If a witness has not immediately experienced something, but merely makes a judgement that things have happened so and we cannot say what their judgement is based on, their testimony is as good as nothing. Also, if it seems quite possible that a witness could have erred or is speaking partially, they are to be deemed unreliable. Then again, Crusius states, if the witness gives an unforced account of a remarkably long, but still coherent series of events, this suggests that the tale is credible. Further indications of credibility, he suggests, are modest acknowledgements the witness makes of their own ignorance and sudden revelations of things the witness should have been quiet about (although the latter can also be, Crucius admits, a sign of a naive or a rash person).

Crusius warns that we should not confuse credibility of a single event and credibility of a historian in general. The latter can give credence to the former, but it is not the only possible justification for an event; besides, before becoming a credible historian, a person has usually established credibility of many historical events. Crusius also reminds the reader that they should distinguish between immediate and mediate witnesses. Immediate witnesses have themselves experienced something and then the question is, whether their experience has been complete enough and whether they have reported it faithfully. A mediate witness, on the other hand, has relied on the accounts of others, public records and other sources, and then the question is more about the credibility of these primary sources and about the ability of the mediate witness to use them without making things up on their own. Usually, Crusius thinks, immediate witnesses are to be preferred over mediate witnesses, although sometimes the immediate witnesses might not have had the opportunity to observe the event from all angles (for instance, a single soldier might understand less about the ongoings of a war than a researcher who has studied its course for a long time). Similarly, he points out, historians living closer to the time of an event are usually more reliable than later historians, but geographical distance, lack of understanding of the context (e.g. when a person of an upper class writes of the ongoings of the lower class) or partiality can weigh the balance on the side of the later historian.

Crusius thinks that historians relying on proofs lose their credibility, if we observe them using unwarranted sources or contradicting themselves. Then again, he states, mere unfortunate speculations about reasons of events do not destroy their credibility, if they just clearly distinguish these speculations from established historical events. If we are reading a work of an unreliable historian, Crusius continues, we should believe only such things, which seem in itself possible or probable or which are confirmed by other witnesses or justifications. He is also of the opinion that a single unfounded treatise should not make us suspect the historian in general, just like a single error should not make us suspect the whole treatise.

Crusius warns not to take a lack of mention of an event by historians as evidence of the event not happening. If we want to do so, he explains, we should show that there are no understandable reasons for their silence, such as a fear of state officials or religious beliefs, or we should show that being silent on a major event would contradict the character of the writers. Then again, much stronger evidence against the truth of some event than mere absence of mention, Crusius thinks, is provided by an account of a historian explicitly contradicting the supposed historical event.

This leads us to the question what to do, when historians give conflicting accounts. Crusius suggests that in these cases we must observe the individual circumstances of the writers: for instance, whether they count the time differently or whether they speak only of similar events. Sometimes nothing more is needed than clearer definitions of words, he assures the reader. Whatever we suggest for explaining the seeming conflict, Crusius underlines, we have to consider whether we want to show that the suggestion is true – then we need to prove it – or whether we just try to justify the credibility of the historians – then it is enough that our suggestion is a real possibility. Crusius concludes by insisting that a conflict of historians requiring explanation does not necessarily weaken the credibility of their accounts and a good explanation might even strengthen their credibility.

Crusius concludes the chapter with the question whether the length of time that has passed from the event takes away from its credibility. His answer is essentially negative: the existence of triumvirate in Rome is as believable now as it was during the age of Charlemagne. True, he admits, we might have less justifications to believe an event to be true, especially if we find new evidence to refute earlier accounts. Then again, the credibility might, on the contrary, also increase through new evidence, he notes, so that what was earlier just a widely spread rumor, might in the new circumstances become credible history.

Crusius, Christian August: Road to certainty and reliability – Research and teaching

Like the logic textbooks of the time often did, the final few chapters of the work of Crusius treat the question how to apply everything previously said to the practices of scholarly work. Crusius speaks more precisely of meditation, by which he means a process of extending our knowledge further from some fundamental thoughts. In addition, he considers also the related problematic of how to transmit the internal meditation to others in a scholarly treatise, which requires accommodating the results of meditation to their needs. Crusius also ponders the practices of disputation, but has not that much new and interesting to say about the topic, so we’ll ignore it.

Quite traditionally, Crusius distinguishes two different types of meditation: analysis, where we try to make our knowledge of the fundamental thoughts more distinct, complete and certain, and synthesis, where we progress from fundamental thoughts to other truths that are not its part nor grounds, but are merely inferred from it. He notes that both actual meditation and scholarly treatises use both methods and that sometimes even individual pages in treatises can have many occasions of both methods.

In the synthetical method, Crusius thinks, the fundamental thoughts studied must always be concepts, but the analytical method can also have as its object words, the meaning of which is sought out. Thus, he argues, the analytical method is divided into analysis of things or concepts and analysis of words or terms. Starting with the analysis of concepts, Crusius divides it again into analysis of parts, which sets out distinctly all the parts and internal determinations of the fundamental thoughts, and analysis of reasons, which looks for proofs for the fundamental thoughts and evaluates proofs suggested by others. The difference of the latter from the synthetical method, he explains, is that we are usually convinced of the proof of the fundamental thoughts and we just want to make this conviction more secure.

Crusius divides the analysis of parts again into merely resolving analysis, which sets apart distinctly just what is already in the fundamental thought, and determining analysis, which adds further determinations to what is still indeterminate in the fundamental thought. He calls the latter also mixed analysis, because it often has to use also the synthetical method, although for an analytical purpose. This determining or mixed analysis, Crusius explains, adds either determinations that belong to the object all the time and thus are part of its essence or determinations that belong to the object disjunctively through divisions.

Crusius notes that the methods of analysis of parts and analysis of reasons can also be combined. This combined method is especially used, he explains, with problems, where we start from given data and progress to the grounds, on which the data depends, and generate from the characteristic or quantity of the grounds the required characteristic or quantity. In this method, Crucius points out, the first move toward grounds is analysis of reasons, while using the grounds to make the previously unknown determination distinct is determining analysis. He points out that this method is especially used in mathematics, under the name of algebraic method, when we are asked for a magnitude of something and we determine it through other magnitudes, on which the first one depends.

Analysis of words or texts Crusius divides into three types. Firstly, it may be about interpreting a text, it may be about outlining the order or disposition of the text or it may be about evaluating the worth of the text. The interpretation is something Crusius will return to in the final chapter of the book, so he in this point merely divides disposition of text into natural disposition, which follows the goal of the author, and artificial disposition, which follows any convenient general concept, and divides evaluation of the text into evaluation of the writing style and into evaluation of the thoughts in it.

Crusius lists three kinds of synthetical method, which he names after the sciences prominently using them. First of them is the geometric or mathematical method, which takes as its starting point the concept of a possible essence. The second, then, is the physical or experimental method, which starts from propositions involving physical existence. The final one is the moral method, which begins with propositions involving moral existence. Crusius notes that the physical and the moral method together can be called the philosophical method.

Crusius goes through the different types of synthetical method in more detail, starting with the mathematical or geometrical method, where the possible essence it begins with is such that the existence of which is not yet posited or at least not yet considered. This method then proceeds to find out more about the relations and consequences of the essence and discusses problems following from these. Crusius notes that the specialty of the geometrical method is that it does not prove its definitions, but just postulates them as possible. Thus, he argues, propositions shown by it have only a hypothetical reality, which is enough for pure mathematics. Then again, Crusius points out, the geometrical method is used elsewhere, for instance, in studying the relations of possible essences.

The physical method, Crusius continues, starts from experiences or real propositions deduced from experiences – he notes that all existences must in the end be justified from experiences. The method then proceeds to other propositions involving physical existence or real possibilities. In other words, Crusius explains, the physical method moves from effects and properties of things, known by experience, to their causes, further effects and relations. The method is used, naturally, in physics and also in medicine, which Crusius takes to be a special subspecies of physics. He notes that this method is used also elsewhere, for instance, in revealed theology, where the Bible takes the place of experiences.

Moral method, finally, proceeds from fundamental thoughts to the purposes of things or from posited purposes to other purposes, whether these purposes concern human happiness or moral laws. In case of moral laws, Crusius thinks that we know them sometimes through sensation – when we are speaking of written or announced laws – and if we are speaking of natural laws, we can know them by deducing from experience, although he warns the reader not to confuse inferences from what makes us happy for a proof of moral law. Crusius also points out that studies of moral existence or possibility should not be confused with studies of efficient causes and means that make certain conditions of mind possible or actual, because the latter demand the physical method. Then again, he adds, most moral topics also require these physical investigations.

Crusius states that the synthetical method cannot be applied before the fundamental thoughts are distinct and known to be real or at least possible, which presupposes that we know definitions, experiences and other propositions. Definitions in particular, he says, should at least be resolved into axioms, and if this is not enough, determining analysis is required. Thus, Crusius argues, both analysis and synthesis are required in meditation, but synthesis presupposes analysis. Furthermore, he continues, each thing must be studied according to its nature. For instance, existence must be studied analytically and especially through determining analysis or synthetically with physical or moral method or often by both means, while study of essence requires mathematical method or analysis.

Crusius also gives some general guidelines on how to go about in meditation of things. A central concept here is the theme of meditation, by which he means its main or objective purpose. The theme is either simple – a concept, a proposition or a problem – or composed of many simple themes. If the theme is something arbitrarily made by humans, Crusius says, we should check whether it is useful to investigate it. With naturally generated things this check is not required, he thinks, because knowledge of such things enriches the sciences and influences many truths.

In order that meditation will be useful, Crusius explains, we should already have some capacities for meditation, which requires a diligent and thorough study of logic. In addition, he notes, meditation requires materials, which are supplied by preliminary knowledge that helps to form concrete ideas, both on the general structure of all sciences and particularly on sciences close to the theme investigated. Crusius also instructs the reader to learn about history, because historical knowledge can provide experiences and understanding on causes of many possibilities.

After gathering this preliminary knowledge, Crusius explains, the meditation starts by directing attention to the fundamental thoughts and trying to think them lively and ever more perfectly. This means, he adds, reflecting on and analysing examples that fit the concrete ideas, together with the opposites of these examples and the predicates that are ascribed to the examples through the concrete ideas. In addition, we should recollect what we have heard and read about the topic and perhaps collect more experiences about it. When all of this is done, Crusius suggests, we should draw an outline of the meditation to guide our imagination, by determining the main points in the theme, to which meditation should be directed.

Once we have fixed the purpose of meditation, Crusius insists, we should make a special theme about the requirements of the method. This means, firstly, he explains, planning a good order for the meditation or the treatise made through it. The general rule, Crusius says, is to start with that without which the following cannot be understood, at least not as conveniently. This does not mean, he clarifies, that nature would determine the place for each thought so precisely that they could not change their places, because there’s much arbitrary in the order of meditation and scholarly treatises.

Something peculiar to treatises, in opposition to meditation, Crusius suggests, is that although in meditation scholars should be ready to reduce everything to first grounds of all sciences, it would be too difficult to do that for every proposition and often superfluous in the eyes of the reader. Still, he adds, we should not assume as familiar what is doubtful and we should try to find justifications even for familiar truths, especially if this is a key to finding desired truths, or to shying away from difficulties.

Crusius suggests that the working of themes is easier, when their main points are classified and ordered under a few titles – he calls this classification by the Aristotelian term topics. I shall skip this part of the chapter, because it consists mostly of titles of the treatise to be made.