Words, Phrases, and Definitions to Broaden your Greek Mind

I am reasoning (subjectively) to a conclusion. Συλλογισμός is where the English word ''Syllogism'' comes from: a logical thought process that follows certain premises to a conclusion.

Συλλογισμός (si-lo-gi-smos)
- Εγώ συλλογίζομαι

Influence
I am influencing someone or something.

Επιρροή (e-pi-ro-i)
- Εγώ επηρεάζω

Presupposition / Assumption
I presupposing something as true prior to any contrary evidence, and it effects my reasoning processes.

Προϋπόθεση (pro-e-po-the-si)
- Εγώ προϋποθέτω

Worldview
A person's overall opinion for the existence of life, the existence of the universe, the existence of intelligence, of  morality and life in general.

Κοσμοθεωρία (ko-smo-the-o-ria)

To overturn / subvert a power of authority, previous plans or standards, or of a system of thought.

Ineffectual
To have no effect. The word Άκαρπο translates to ''Fruitless'' - as καρπός means fruit and the 'Α' as prefix is the negation thereof.

Αναποτελεσματικό (A-na-po-te-le-sma-ti-ko)
- Synonym: Άκαρπο (A-kar-po)

Suspicion
I am suspicious.

In Greek culture, this word does not necessarily have a negative connotation. Whereas in English, ''being suspicious'' almost always insinuates something bad.

Υποψία (I-po-psia)
- Εγω υποψιάζομαι

Impartiality / being unbiased
- He is impartial and doesn't discriminate

Αμεροληψία (A-me-ro-li-psia)
- Αυτός είναι αμερόληπτος και δεν κάνει διακρίσεις.

Prejudice
Someone who has formed a presupposed opinion towards a person or matter and does not change their stance easily.

Προκατειλημμένος (pro-ka-ti-li-me-nos)

Αρετή is a trait or quality that is deemed to be morally good and thus valued as a foundational principle for moral behavior: a high moral standard

Principle: 
Although the Greek word Αρχή also means '' beginning'' - which shines more light at what principle means: ''where things begin and are measured from'' 

- The straight line by which we measure any deviations.

Faith
Πίστη is the conviction of things hoped for, and the evidence for things not seen (or of intangible things).

Πίστη also means trust, commitment, devotion or a love for something or someone not of this world.

Potential / Possible
It denotes something that may happen or exist, but hasn't been confirmed yet.

Actualisation
When a potential is actualised; comes into being.

Πραγματοποίηση (Pra-gma-to-pi-i-si)

Obligation
It refers to a duty or responsibility that one is bound to fulfill.

The word Λόγος is one of the most foundational works in the Greek language. This words can be used for ''Reason'', ''Logic'' (this is where the word logic derives from), 
also for ''Word'', and/or ''Purpose''