Mono no aware (物の哀れ), lit. 'the pathos of things', and also translated as 'an empathy toward things', or 'a sensitivity to ephemera', is a Japanese idiom for the awareness of impermanence , or transience of things, and both a transient gentle sadness at their passing as well as a longer, deeper gentle sadness about this state being the reality of life.

Impermanence, also known as the philosophical problem of change, is a philosophical concept addressed in a variety of religions and philosophies. In Eastern philosophy it is notable for its role in the Buddhist three marks of existence. It is also an element of Hinduism. In Western philosophy it is most famously known through its first appearance in Greek philosophy in the writings of Heraclitus and in his doctrine of panta rhei. In Western philosophy the concept is also referred to as becoming.