A statement can not be true and false at the same time.
A thing without oppositions ipso facto does not exist … existence lies in opposition.” — CS Peirce
“It is the hallmark of any deep truth that its negation is also a deep truth.” —Niels Bohr
“The heart’s wave would never have risen up so beautifully in its cloud of spray, and become spirit, were it not for the grim old cliff of destiny standing in its way…” — Friedrich Hölderlin