-"All men, by nature, desire to know."
-Opening line of Aristotle's Metaphysics.
-Seems as if Aristotle is suggesting that the quest for knowledge isn't just something exclusive to philosophers- it's something that appeals to everyone. Of course, just because we want knowledge doesn't mean we always get knowledge.
-Of course, what exactly is knowledge?
-This is the core question of epistemology (the study of knowledge).
-Epistemology is based on the distinction between knowledge and belief (an idea first introduced to us by Plato in works such as the Meno and Theaetetus, and in the Republic it seems as if Plato is arguing that the average joe has "beliefs", whereas philosophers (who also happen to be elites) use dialectic to attain "knowledge".
-Like Plato, Aristotle sees the attainment of knowledge as something that is both difficult to achieve and reserved for elites (we learn about this in Aristotle's work Posterior Analytics (the "posterior" part of the title is presumably meant to contrast with Aristotle's other work Prior Analytics, which discusses logic and the rules governing valid arguments), which discusses which valid arguments lead to the attainment of knowledge).
-Posterior Analytics seems to be the closest we can get to an Aristotelian treatise on the subject of epistemology.
-What are the conditions in which someone can be sure that they actually "know" something?
-Aristotle says that you can be sure that you know something when you can demonstrate it.
-Aristotle covers what valid arguments are and how to make them in Prior Analytics, which is why that work is such an essential accompaniment to Posterior Analytics; you demonstrate knowledge by making valid arguments (of which satisfy Aristotle's criteria)!
-So, what are the criteria for a valid argument?
-According to Aristotle, a valid argument first needs to have two premises that have one term in common. When put together, these two premises yield a conclusion (this is called a "syllogism" (Greek: "syllogismos" ("conclusion, inference")) by Aristotle). Thus, demonstrations of knowledge are syllogisms.
-These syllogisms should be explanatory. For example: "Giraffes are land animals that eat leaves off of tall trees. Land animals that eat leaves off of tall trees have long necks. Therefore, giraffes have long necks." As we can see, the middle term ("Land animals that eat leaves off of tall trees have long necks") links the first premise and the conclusion.
-Additionally, in order to understand something we need to have an explanation for a whole class of things, not just one particular thing. In other words, this understanding must be universal. For example, if we say that Hiawatha, a giraffe, has a long neck because she eats leaves off of tall trees, that doesn't really count as knowledge or understanding according to Aristotle. Instead, if we say that Hiawatha has a long neck because she is a giraffe, then THAT is understanding because we know that having long necks is a universal characteristic of all giraffes.
-Of course, this gets into what Aristotle calls "accidental" and "essential" features.
-"Essential" features are characteristics that something has as a result of its nature. These features are shared with all other members of that thing's kind.
-"Accidental" features are characteristics that something has, but not as a result of its nature.
-Furthermore, premises of a demonstrative argument MUST mention essential (see above) features of the things that they are explaining.
-It is worth noting that based on this logic, Aristotle is implying that there is no knowledge or understanding of accidental features. This is interesting because although Aristotle set the groundwork for modern-day science, "accidental features" are extremely relevant for scientists in terms of understanding something.
-Aristotle actually used the word "epistēmē" for a bunch of different subjects such as math, science, metaphysics, etc., as for him they were all branches of knowledge as a whole.
-Thus, with Posterior Analytics Aristotle sets out to create a sort of scientific "program".
-According to Posterior Analytics, science allows us to acquire explanations for things. These explanations are universal and are based on "essential" (as opposed to "accidental") features.
-One interesting point Aristotle makes in Posterior Analytics is that we can only "know" something if it is true. Thus, he concludes that if the things I know can't be false, then they are NECESSARILY true; when he demonstrates something, not only will he have premises and a conclusion which address with universal and essential features of things, but he will also have premises and conclusions that are ALWAYS guaranteed to be true.
-For example, we can know that giraffes have long necks because having a long neck is an essential feature of a giraffe; giraffes must NECESSARILY have necks in order for them to be giraffes. A giraffe MUST have a long neck in order for it to be a giraffe.
-Of course, this can be challenged by modern science because we now know about evolution and shit like that. According to Aristotle's logic, the idea that giraffes at some point in time didn't exist and that at some point in the future they will most likely be extinct is impossible because all knowledge is based on eternal truths. If giraffes didn't exist at some point in the past then how could we have any knowledge of them in the present?
-A modern day update of this would probably say something along the lines of- "IF something is a giraffe, then it has a long neck."
-Aristotle also writes that the knowledge gained from a conclusion can only be as good as the knowledge of the premise(s) used to support it.
-For example, let's use the demonstration that giraffes have long necks (conclusion) because they eat leaves off of tall trees (premise). However, if we don't know why giraffes eat leaves off of all trees, then it seems like we don't know why giraffes have long necks, either.
-Thus, our understanding of the conclusion can only be as good as our understanding of the premise(s).
-Of course, this can become a huge problem- if a demonstration's premises also involve a demonstration, then we could just do this forever in a never-ending loop of demonstrations followed by premises which require demonstrations.
-Aristotle addresses this problem at the very end of the text by saying that eventually this seemingly never-ending loop must come to an end; however, it must also not be circular.
-Aristotle makes the point that every demonstrative argument must ultimately derive from a "first principle", and that our understanding of these first principles must be stronger than our understanding of what we are demonstrating (through these first principles).
-This is the beginning of a school of thought that would eventually come to be known as Foundationalism- the idea that all knowledge is grounded upon "fundamental truths.
-Of course, these fundamental truths aren't demonstrated (what a cop-out!), but Aristotle argues that everyone already knows these fundamental truths, although he dismisses the argument that we know these fundamental truths BUT are unaware of them (i.e. Plato's "Theory of Recollection"). Instead, Aristotle argues that we know these fundamental truths through repeated experiences based on our senses.
-Aristotle expands upon this by using a phalanx as an analogy: as a phalanx turns to fight after retreating for some time, its formation is restored. Each hoplite that turns to fight may seem like he is having is own individual experience, but when the phalanx snaps back into formation as a whole that is like universal knowledge entering our minds.
-So, is Aristotle an empiricist (believing that all knowledge is based on sense-experience)? It would be a mistake to say so, as the empiricists were influenced by skepticism. Aristotle believed that all of our minds were able to perceive the world as it is without any problems. Additionally, Aristotle didn't believe that all of our knowledge comes from sensation, as Aristotle was could still be critical of commonly-held opinions.
-Aristotle wanted to focus on arguing from what already seems plausible, even though it's possible that what may seem plausible can ultimately be proven wrong.
