Metaphysics is the inquiry into the nature of things — which has tended to mean their 'first principles'.
The result of this inquiry has tended to be abstract and rationalistic. Existentialism is a movement with
its origins in Christian philosophy, although it is best epitomised (and normally characterised) by
twentieth century atheist philosophers like Sartre and Camus. Existentialism is not just a 'movement'
of philosophy, but a timeless tendency to bring thinkers back to the conditions of existence. The
inquiry into the nature of things — their whatness — traditionally led to talk of their essence. For
example, humans have a 'nature' and humans partake of their nature, which is their essence,
because it is common to all: a materiality and certain form, capacity for freedom, and good, language,
immortality, mortality etc. Discussion of these 'essential' matters find their balance in the existential
tendency which reminds philosophers that I cannot experience myself as an essence. In thinking
about whatI am, lets not forget thatI am.