In his philosophical works, Aristotle often employs an overarching approach that - following his own terminology - we typically call "Dialectical". This is not a term that Aristotle himself invented, but rather which he inherited from his own teacher, Plato, who mentions it at numerous places in his dialogues. It is important to distinguish what, following Aristotle, other ancient and medieval philosophers continued to call "dialectic" from the later meaning of the term that was given to it in the Hegelian and Marxist traditions in the 19th and 20th century.

Aristotle will rework and give additional specificity to the notion of dialectic in his own works, particularly in a work that is called the Topics. Some summary of the position he develops in the first book of that work, which are relevant to the kind of inquiry that he carries out in the Nicomachean Ethics, can be found below. Before that, however, it can be useful to consider six distinctive features of Aristotle' philosophical approach that, once pointed out, you'll have little trouble seeing as you read and reread his text. These are:

• Asking Leading Questions: Aristotle will, at many junctures in his text, raise questions about the matter under discussion. He does this because he is engaged in genuine inquiry, not just telling you what he thinks or has figured out, but starting on the path to inquiry, or opening up new paths from the main one. He does not presume that you have yourself already realized that these are important questions to ask.
• Canvassing Other People's Ideas: You will see Aristotle over and over again bringing up what other philosophers, playwrights, poets, politicians have to say about a topic, even sometimes quoting proverbs of the sort that "everybody knows" -- that are part of the culture he inhabits. He does this because there is likely something to be learned from each of these perspectives -- even if they are not entirely correct, and are actually wrong on some points, they can provide us with some bits of truth
• Drawing Inferences from Observation: Aristotle famously differs from Plato by placing much less stress on contemplation of ideas and much more on empirical observation of things in the visible, tangible, material world. If you want to know how or what something is, you ought to observe it, thereby gaining experience about it, which then you reflect upon. It works this was with natural phenomena, and it works this way with people. If, for instance, you want to know what someone really does value, watch them, see what kind of decisions they make, what kind of life they pursue.
• Identifying, Distinguishing, and Connecting Key Concepts: Aristotle will introduce you to many key concepts in the course of studying a topic. He is anything but simplistic, because the realities he wants to study -- especially those dealing with human nature and the moral life -- are complicated, interconnected, and often controversial. Because they are connected with each other the concepts -- when you understand them -- illuminate each other. You'll find as you put in the time and work to understand some of the concepts, your understanding of other related concepts also improves.
• Approaching Matters from Multiple Angles: You will notice at points that Aristotle will say things like: Let us now make a new start," or "Let us now go back to the topi we were discussing." Reality is complex, and often we have to approach the realities we want to study and understand from multiple angles, multiple points of view, multiple ways of considering it. And, sometimes, it's not enough just to think about it -- or even think it through -- once. In order to really understand something, you have to be willing to go back to it after you have added some new ideas or experiences to your tools.
• Appropriating What's True, Integrating It, and Going Further: Aristotle is willing to draw on practically any source which will advance our knowledge - to the degree that it does -- critically. This means that a central activity of his dialectical method is examining and assessing the degree of truth in whatever sources he starts with in approaching a topic. Then, what we know, what we determine to be true has to be integrated -- connected to each other systematically. We have to see if there are any hidden contradictions. We also have to follow out leads that other thinkers didn't notice -- going beyond them to provide a more adequate understanding of the topic

What Is Dialectic?

In another work, called the Topics, Aristotle begins by telling us that dialectic is a kind of inquiry or method that involves reasoning from generally accepted premises about all varieties of topics or subject matters. There are found components here in this proposed definition of "dialectic", and each of them are worth thinking about a bit.

• Dialectic is what Aristotle calls in Greek a "methodos", a kind of study, an inquiry, a fairly systematic way of doing something. So, not just any random talking or putting words together can qualify as dialectic. It's also something that a person can learn how to do, and get better at doing. Keep in mind that this term, methodos, shows up in the very first sentence of the Nicomachean Ethics.
• Dialectic also has at its very heart reasoning, or more literally "syllogizing" - i.e. creating, using, testing, and opposing syllogisms about the matters of discussion. A syllogism later came to be formalized into a particular kind of argument -- but what Aristotle has here is some sort of connected chain of reasoning, not necessarily the three-proposition form of syllogism.
• Dialectic takes as its starting points -- its "raw material," you might say -- premises that are generally accepted as solid, likely, probable.
• Dialectic also ranges over all of the possible subject matters that can be discussed. It is not by its very nature confined to one single topic, issue, or matter.

In a related text, the Rhetoric, Aristotle also famously tells us that "rhetoric is the counterpart to dialectic" - Rhetoric is also concerned with argument, and ranges over subject matters, but is different from dialectic by being less rigorous and being concerned with finding means to produce persuasion, rather than with the objects of dialectic.

He also tells us something else very interesting: everyone has some share in both dialectic and rhetoric - even if one has not studied them or even heard of them. How can this be? Everyone, in some way or another, in the course of their life, tries to break down or to uphold an argument, to defend or justify themselves, or to criticize another person for something. These are basic - and very common - acts in human communication. Dialectic helps us to do these sorts of things well.

Dialectic and Other Kinds of Reasoning or Argument:

Aristotle distinguishes dialectic from several other kinds of reasoning or argument - and so, by learning what dialectic is not, we might get a better understanding about what in fact it is. As we've already seen, although they are related (Aristotle actually calls rhetoric an "offshoot", a part, or a "likeness" of dialectic in the Rhetoric), rhetoric and dialectic are actually two different, distinguishable studies

• one - rhetoric - is concerned with figuring out how to produce persuasion about different issues
• the other - dialectic - is concerned with determining practical matters of choice and avoidance, or theoretical matters of truth and falsity

What else can dialectic be contrasted with?

• Demonstration (apodeixis) - this is reasoning where the starting points have a different level of certainty or acceptance to it than dialectical reasoning. Deductive reasoning, where the premises are true and primary - and we're certain of them - fits this type. What it means for premises to be "primary" is that it doesn't really make sense to keep asking Why? about them. An example of this kind of reasoning would be mathematical proofs.
• Contentious (eristikos) Reasoning - this is different from dialectic in that it uses starting points that are only apparently generally accepted, or reasoning that only appears to start from generally accepted starting points, but in actuality does not. Contentious reasoning uses fallacious or flawed reasoning
• Reasoning in Other Disciplines - there are a number of sciences, crafts, and arts, each of which has its specific subject-matter, about which it is knowledgeable, and can reliably produce arguments with certainty or a high degree of probability. Generally, the principles or premises from which these arts reason are in fact specialized knowledge, not available to everyone, and not generally accepted (since relatively few people actually know them).
• Misreasonings in Other Disciplines - in this kind of incorrect reasoning, someone begins from what appear to them to be the true, clear, primary premises of the specific disciplines, but they get that wrong

So, what else can we say about dialectic, by contrast to these other kinds of reasonings or uses of argument?

Dialectical Propositions and Problems:

One of the key features of dialectic is what it starts from -- in terms of arguments, we call these premises, in relation to the conclusion we are attempting to argue to. Considered on their own, we can call them propositions -- for they assert something to be or not to be the case. Dialectic begins its reasoning from dialectical premises or propositions.

What makes something specifically a dialectical proposition? According to Aristotle this has to do with their being "generally accepted" -- but what does this mean? He sets out a number of different ways in which this can be the case.

• they might be accepted by everyone -- but they are nonetheless not primary -- you can still call them into question.
• they might not be accepted by everyone , but still be accepted by most people, the majority.
• they might not be accepted by everyone, or even the majority, but are nonetheless accepted by the "wise" (including philosophers), who presumably have thought the matters through, and have some good reason for holding and asserting them

Aristotle will later discuss this last category in a bit more detail, breaking it down further.

• dialectical propositions might be held by all of the wise
• they might be held by most of the wise
• they might be held by just some of the wise, i.e. the most notable - the most reliable and important - of the wise

Aristotle tells us dialectical propositions arise in other ways as well:

• opinions that seem to be in line with views that come from the recognized disciplines - since presumably those people know what they're talking about
• opinions that are connected with other generally accepted propositions by analogy or contraries.

So, the premises or starting points -- these dialectical propositions -- are not matters about which one can be entirely sure. One thinks that they are likely to be true, at least in part, but they are not entirely reliable. They have to do with opinions (doxa), which can be better or worse, right or wrong. In many important subject matters, however, this is the best that we can work with -- this is what we have to "go on", as they say.

This leads us then to dialectical problems - and you can see Aristotle raising and addressing such dialectical problems over and over in his works, particularly in portions of the Nicomachean Ethics. A proposition says that something is or isn't the case. A problem, by contrast, arises when we're not sure about whether something is or is not the case. This is particularly likely to arise when we're dealing with dialectical propositions, precisely because these are matters that tend to be rather murky, on which people tend to have competing views - and often bring forth competing arguments

What is Dialectic Good For?

Aristotle discusses several different uses of dialectic.

Dialectic is useful for intellectual training. It involves studying arguments, and studying arguments -- making them, criticizing them, examining their structure -- is precisely how one comes to become good at dealing with arguments. This sort of training of the mind is not discipline-specific. Instead, it transfers across subject-matters, making a person better at thinking things out, knowing what questions to ask, how to find weak points in other people's (and one's own) arguments

Dialectic is also useful for engaging in discussions with other people. Since one of the things one studies in studying dialectic is precisely the kinds of views or opinions that are generally held, one is able to figure out for the interlocutors one happens to encounter what they might be willing to accept as premises for an argument. Additionally, it will help us in steering the conversation away from incorrect or implausible lines of reasoning or argument towards better ones.

It is very important for doing Philosophy as well, since it enables us to figure out what arguments might be made for and against on the kinds of issues that Philosophy studies. It also helps us determine where truth and falsity lie in the views which we are considering, to make good distinctions about what is true and what is false.

Lastly, dialectic is actually useful where you might not expect it to be - in all of the other disciplines. Each science, art, or other discipline has its own primary assumptions or starting points which it takes for granted, and then reasons from - the discipline, however, does not call into question, or even in many cases really examine those starting points. But, dialectic does do this.