Bernard Bolzano: Study of science (1837)

(1781–1848)

Hearing the title of Bolzano's magnum opus – Wissenschaftslehre – makes a student of German idealism instantly think of Fichte's similarly named treatises. Despite Bolzano's cries against this, the two do share something in common, namely, the attempt to set up a kind of metascience or a science of sciences that acts as a foundation for all other sciences.

The similarities between the two projects do not go far beyond this very abstract foundation. Bolzano's Wissenschaftslehre is a much more modest affair. For Bolzano, science is just a convenient chunk of the sum of all human knowledge that could be presented in an easy to understand and convincing book or treatise presentable in a book. Wissenschaftslehre, for Bolzano, is then in essence a science of rules for making books or treatises from sciences.

Bolzano emphasises the literary character of Wissenschaftslehre: it should not include didactics, which he defines as the science of oral teaching of sciences. Even so, an inevitable question is whether it is possible to write a scientific treatise on Wissenschaftslehre, before one has such a treatise from which to learn the skill. Bolzano notes that it is possible, because it is possible to follow the rules without knowing them distinctly.

Bolzano notes that his planned Wissenschaftslehre is not a new idea, but has been studied under many different names, most often under the name of logic. True, he admits, logic has never really been defined in the same way as he does, probably because the rules of making scientific treatises have formed just a small part of logic. Bolzano finds no difficulty in this, since these other topics are preliminaries we must learn, before getting to the writing of a scientific treatise – a phenomenon familiar with other sciences also.

Reverting to the more familiar name, Bolzano notes that by logic we can mean logic in objective sense – sum of logical truths, no matter whether they are actually known by anyone – logic as an individual treatise and logic in subjective sense – sum of opinions on logical topics of a certain person or subject. Logic in the subjective sense can then be divided into natural logic – sum of logical insights that anyone has without any learning – and artificial logic – sum of logical information gathered through various means of learning. Furthermore, Bolzano notes, logic in the subjective sense can be distinguished from a capacity to follow logical rules, because it is possible to follow logical rules without knowing them and know the rules without being able to follow them. Logical capacity finally divides into innate logical talent and logical art acquired through, for instance, study of sciences.

Bolzano points out that even if we have innate logical skills, studying logic is still good for avoiding mistakes and false deductions and especially useful for very subtle disciplines like metaphysics. In addition, Bolzano says, a logical treatise gives a good example of what a scientific treatise should look like. Still, he does not encourage teaching logic to very young children, because it requires very much abstraction, its topic being so far removed from sensuous matters. Instead one should first study easier disciplines, like natural sciences and a priori sciences that can be sensuously represented, such as geometry.

Bolzano considers some questions about the nature of logic, such as whether it is more of an art or a science. According to his definitions, it is actually both. Crusius defines art as a practical or technical science, that is, a science, the essential content of which lies in rules of behaviour, or in a more stricter sense, as a scientific description of processes one must do to put rules of technical science in practice. Logic, he thinks, is at least a technical science and maybe even art in a stricter sense.

Another question is whether logic is a formal science. Bolzano has some problems understanding what the question means. In a sense, he says, the answer might be positive: logic deals, for instance, not with any determined propositions, but with kinds of propositions (such as affirmative and negative propositions) that might be called their forms. Then again, Bolzano adds, if by formal is meant such a science that abstracts from all differences of objects, logic does not fit the description, because it deals e.g. with difference of empirical and non-empirical truths or that of analytical and synthetical propositions. Even more so, Bolzano states, if by formal science is meant a mere collection of analytical truths, logic, and indeed no real science, is such a collection.

Bolzano considers also the relation of logic to other sciences: is logic dependent on some of them or an independent science? He explains that by a science being dependent on another he means that a treatise of the first science must contain in its demonstrations propositions belonging to the second science. Bolzano points out that very few sciences are independent in this sense. Logic particularly, in his opinion, depends at least on empirical psychology.

The only task left to do for Bolzano before actually starting logic is to consider what preliminaries to study before dealing with the proper science of sciences, that is, showing how the field of truth should be divided into individual sciences and what rules these sciences should follow. Before we can get to the business of constructing sciences, he says, we must obviously have truths to make them. Thus, Bolzano concludes, logic must also contain heuristic or art of finding truths.

Bolzano notes that the proper science of sciences and heuristic cover much of what is usually named methodology. In fact, he says, they contain even more, since usually methodology is taken to be a part of pure logic, containing only truths applicable to all thinking beings, while his science of sciences and heuristic are explicitly dealing with the question of how humans find truths and make sciences out of them. Because of this, Bolzano suggests, logic must also investigate the question how humans can in general know truths, that is, it must deal with epistemology.

It was commonly thought the methodology presupposed what was called elementary science that dealt with concepts or representations, propositions or judgements, deductions or syllogisms and often also truth. Bolzano also accepts this elementary science as a part of logic, since understanding these elements is necessary for understanding how truths can be known and found out. He does make a significant change: while usually the elementary science was meant to be a study of e.g. truths as thoughts, Bolzano argues that it should study something more fundamental, in other words, truths in themselves that need not be thought by anyone.

Elementary science, as conceived by Bolzano, has one further presupposition: in order to study truths in themselves, we must at first ascertain that there are such objective truths, not dependent on any thinker, and that we humans can have access to them. This final – or actually the first – part of logic he calls fundamental science, because all other sciences presuppose it. Next time, we shall start our journey through Bolzano's logic with this fundamental science.