In terminology, exist (CR:1516), from Latin existere “to come into being” (Merriam) or “to step out, stand forth, emerge, appear; be” (OED), from ex- + -sistere “to stand, stop”, refers to something that has physically measureable form; is real or has reality; as opposed to something imaginary, fictional, or mythological (e.g. god, caloric, ether, life, or unicorns, etc.). [1]
Quotes
The following are noted quotes:
“Believe me, dear Sir: there is not in the British Empire a man who more cordially loves a union with Great Britain than I do. But, by the God that made me, I will cease to exist before I yield to a connection on such terms as the British Parliament propose; and in this, I think I speak the sentiments of America.”— Thomas Jefferson (1775), “Letter to John Randolph”, Nov 29 [2]