A dialectical definition of Aristotle's dialectic - Part I

Birds in formation
Using Aristotle's dialectic to define Aristotle's dialectic.


To provide a dialectical definition of dialectic we begin by establishing its genus and then by identifying its differentia to other concepts in the same genus, and finally arrive at its essence. In more Hegalian terms, we are searching for both identity and difference.

Read: An introduction to Aristotle's Dialectic. 

The first step is to place dialectic into a genus.  So how do we define genus? In more contemporary language a genus is basically the more ‘general’ category or class in to which our concept, dialectic, can be placed. Aristotle gives the definition of genus as 'that which is predicated of a number of specifically differing things as part of their nature.'

My interpretation of this is that each thing in the genus shares a significant or fundamental characteristic but are not the same as everything else. So the genus animal would include human, lion, rabbit. So we want to know, ‘to what category of concepts does dialectic belong?’

Intellectual investigation 

The meta-genus to which dialectic belongs is ‘intellectual investigation’. Dialectic is an intellectual practice. It is one of the methods we use to interpret the information that we gather through our senses, and through language.

But it is not the only one. This meta-level genus of intellectual investigation can be divided into the genuses of arts and science. The difference between the arts and the sciences is that the arts are relative - our findings can be different based on the individual person or the material to which they refer; whereas, the sciences search for the absolute or universal - where our findings are true in all cases.

Aristotle places dialectic in the genus of arts along with rhetoric and medicine. These are human practices that take place in a social arena. Even though both rhetoric and dialectic deal with concepts or language, and medicine with plants and bodies, they belong together because they are skilled activities. They are not sciences because they concern individual humans, are subjective. They seek to test definitions rather than attempting to define absolute truth, to discover the one definition.

However, the arts like science do seek knowledge which is generalisable. As Dr Evans points out in Aristotle’s Concept of Dialectic: “[T]he arts - dialectic, rhetoric, medicine - are concerned with the individual perspectives as well as with that which is seen through, and distorted by, them. But the arts too search to achieve universality and objectivity.”

Further: “Dialectic is distinguished from the particular sciences, which are didactic rather than interrogatory and take their start not from views but from premisses which are true and primary.” 


The arts - dialectic, rhetoric, and medicine - also involve the careful selection of materials that can have a desired impact on a specific human being: “[Aristotle] compares dialectic with rhetoric and medicine, and says that in the case of all three faculties the possession of skill is marked by the ability to work successfully with suitable materials; not all materials are suitable, and it is not required of the man who exercises these faculties that he should be able to achieve success with just any materials.”

The art of dialectic uses syllogisms as does the science of logic, but does so in subtly different way: the premises used in dialectic are sought from or agreed with a specific human individual engaged in a dialectic debate. Its aim is to validate and invalidate arguments, and to discover truths. It is concerned with testing the claims of a specific person through question and answers to establish what the premises, logical argument and conclusions used are, and whether they are valid. Logic is concerned with objectively true premises.

As Dr Evans points out: “The study of the apparent syllogisms must be organised on the basis of some selection among the varieties of ways in which people may be deceived; and it is this organisation and selection which makes this study an art. A science must study a concept in its absolute form.”

This affirms that dialectic belongs to the genus of art - and not the genus of science. It is concerned with opinion. You begin not with what is irrefutable (such as established scientific fact) but instead with what the person you are in conversation takes to be true. This is to bring them towards a state of a higher understanding, but also means that dialectic can be used in complex areas of life where no such truth is yet established.


We now move to differentia - the things that make dialectic stand out from other concepts in the same genus. Differentia are those properties that allows us to distinguish from one thing (an object or concept) and an other.

The subject - the thing being described - is qualified by the predicate - the thing being used to describe the subject. A genus is a class (or collection) of things that share a defining predicate. The differentia is the property of any subject that makes it distinguishable from other subjects in the same genus. Therefore, in Dr Evans phrase, that “every differentia is felt to show some qualified thing.” (109) 

Dialectic - for Aristotle - belongs to the same metagenus as logic in that both are intellectual activities. Indeed, dialectic is a debate between two individuals who use logic to test arguments. Dialectic and logic both rely on the use of premises, inference and conclusions - and also the syllogism.

The differentia between dialectic and logic are primarily 1. Dialectic is deployed in debate with a specific individual while logic is not; 2. Dialectic can make use of premises that have not been established as absolute truth, as pure logic should not.

Dr Evans observes: “So there are two ways in which we may have to qualify the absolute character of the dialectical argument - by reference to the other people involved in the dialectical exercise, or to the nature of the problem which we are dealing (81).” These differences mean that dialectic belongs in the genus art, whereas logic belongs in the genus science. 


Let us explore further these two essential differences further: Let’s begin at 1. Aristotle says of dialectic: “All this sort of thing is relative to another person”. It’s about the person you are in dialogue with. Dr Evans interprets this in the following way: "[D]ialectic is necessarily concerned with the individual and his logical reactions, since in the practice of dialectic it is only with individuals that one can deal.” (75) He adds later: “In serious dialectic it is important to be clear about whose views, if indeed they are those of any particular person, are being examined”. (81)

This has significant implications. I have often heard it asserted that dialectic means that everything is part of a whole, and that everything is connected. This does not apply to Aristotle’s dialectic.

Dialectic has no axioms, nor does it have any findings. It is the process of moving from premises to conclusions through question and answer between two individuals. Aristotle is clear that there is a difference between dialectic and ontology, the theory of reality.

Even though his ontology does posit that everything is part of a whole, this argument is not seen as a property of dialectic. Dr Evans writes: “Aristotle ... makes the distinction ... between ontology, which studies everything in the respect in which all things constitute a unity, and dialectic, which does not as an intellectual activity have such a structure as to reflect any unity in the subjects which it treats…”

The individual

There is another fundamental feature of dialectic which results from its concern with that a specific individual knows or argues. Logic - according to Aristotle - attempts to establish a single, central universality.

Universal refers to the qualifier “all” in the class of claim that takes the form of “all s is p”. This essentially means that we are looking for propositions that state all something shares a particular property, or belongs to the same genus.

For example, ‘all humans are animals’. Logic, in the end, is looking for the all of everything. The aim of logic ultimately is to establish a single truth. Dr Evans explains: “[Dialectic] is not the same as the ideal of pure logic, which is to free the conditions of proof from dependence on the variations which may be imposed by the audience or the problems treated (92).”

However, dialectic accounts for two types of universality - the central and the peripheral. The central universality is the object of study of logic. The logician is seeking universals that describe objects and concepts with a single definition which is true in all cases.

Dialectic can make use of both central universality, as established with logic, and also peripheral universality. An example of this is the claim “all humans are good”. It is a universal statement because it refers to “all” humans, and therefore is not a particular statement that refers only to “some” humans. But it is not - or at least not here - predicated on a long coherent chain of argument back to first principles as it would need to be to qualify as a central universality.

If your interlocutor in dialectical argument agrees with you that “all humans are good”, you can start here and infer conclusions from it, but cannot play this fast and loose when engaged in pure logic. 


Dr Evans puts it like this: “[T]he nature of dialectic is determined by the fact that it employs certain concepts which, as Aristotle's analysis shows, possess a double type of universality; these are the type of universality which characterises the concept in its central and primary form, and the type which characterises it in all its forms, peripheral as well as central. It was the distinction between these two forms of universality which was the basis for the analysis of the relation between dialectic and science”. (105).

In reality, every attempt to define the world relates to the person attempting such a definition. It is not possible, in the end, to be completely objective. Even objectivity itself is defined by being separate to the subject.

The real, human, subject is necessary to hold the concept of objectivity. Logic is nonetheless the attempt at establishing propositions which are universal and objective entirely, are free of the subject.

Dr Evans puts it like this: “For such subjects as proof, argument, inference, all contain a reference to the subjects who exercise or experience these things. The study of logic seeks to free these concepts from their dependence on the subjects and to establish theses about them which are objectively and universally valid, and only if it can achieve this do we allow that the study of logic is a skillful activity…” (74) This is not the case with dialectic.

This Author 

Brendan Montague is editor of The Ecologist. This article is part of the Endoxa.review project. 

Page references given refer to J. D. G Evans, Aristotle’s Concept of the Dialectic (Cambridge: Cambridge University Press, 1978).

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