A Posteriori: Knowledge that can only be acquired from experience of the external world.
 

A Priori: Knowledge that can be acquired without experience of the external world, through thought alone.
 

Abductive Argument: These arguments focus on finding the best or most plausible explanation for a given observation or phenomenon.
 

Analytic Truth: True in virtue of the meaning of the words. Cannot be denied without resulting in a logical contradiction.
 

Anamnesis: Recollection, especially of a supposed previous existence. 
 

Arête: property/virtue that enables a thing to achieve its ergon​.
 

Behavioural dispositions: A tendency or capacity to behave in certain ways under certain conditions.
It’s not an actual behaviour but a pattern of how someone would behave if the relevant circumstances arose.
 

Categorical: In all cases​
 

Clear Idea: An idea you can grasp without confusion or ambiguity (e.g., triangle = three sides).
 

Deduction: A method of deriving true propositions from other true propositions (using reason).
 

Deontological: Ethics based on duty​
 

Distinct Idea: An idea that is unmistakably separate from all others with no potential for overlap (e.g., triangle ≠ square).
 

Empiricism: Knowledge gained through experience.
 

Epiphenomenalism: The physical world can cause mental states but mental states cannot cause changes in the physical world​
 

Ergon: function/characteristic activity of a thing​.
 

Eudaimonia: Human Flourishing.
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Hypothetical: In some cases​
 

Imperative: A moral statement​
 

Innatism: We are born with some knowledge already.
 

Intensionality: When the truth of a statement depends on someone’s beliefs, knowledge, doubts, or perspective, rather than on objective facts. It is not necessarily wrong, but it becomes incorrect when you use these types of statements to imply a fact about reality.
 

Interactionism: The mind can interact with the physical world and the physical world can interact with the mind​
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Intuition: The ability to know something is true just by thinking about it.
 

Metaphysics: The study of the nature of reality and what exists.
 

Ontology: The branch of philosophy that examines what exists, what it means for something to exist, and the basic categories of being.
 

Phronesis: Practical wisdom, understanding of a situation before applying the virtuous action.
 

Postulate: Suggest or assume the existence of​
 

Predicate: A property or quality that can be said of something. For example, in the statement “The grass is green,” “green” is a predicate. It tells us something about the grass
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Qualia: The subjective, felt qualities of experience, what it’s like to taste, see, feel, or smell something
 

Rationalism: We can acquire some knowledge purely through intuition and deduction.
 

Sense Data: The content of what we experience and perceive.​ It’s not a physical thing, it exists in the mind. It is both caused by and represents mind-independent physical objects. It is private so no one else can experience your sense data.
 

Summum Bonum: Highest good 
 

Supervenience: A relationship between two sets of properties where the higher-level properties depend on the lower-level properties such that there cannot be a difference in the higher-level properties without some difference in the lower-level ones
 

Synthetic Truth: True in virtue of how the world is. Denial of a synthetic truth does not lead to a logical contradiction.
 

Tabula Rasa: Blank Slate