1The level of goodness or badness of something; the standard of quality or workmanship.
このワインは質が高く、香りも豊かだ。
This wine is of high quality, with a rich aroma.
値段だけでなく、製品の質にもこだわってほしい。
I'd like you to care about the product's quality, not just the price.
この会社は、量より質を重視する方針だ。
This company's policy is to value quality over quantity.
2The inherent nature or character of a thing or person; used with a nuance close to "nature" or "disposition."
この問題の質をよく理解することが大切だ。
It's important to properly understand the nature of this problem.
話し方から、なんとなくその人の質が伝わってくる。
You can somehow sense a person's character from the way they speak.
3A term used in logic and philosophy referring to a specific attribute or property that a proposition or object possesses.
哲学の授業で、感覚の質について議論した。
In philosophy class, we discussed the qualities of perception.