Who said "Technique is the outward sign of an inner conviction."?

This quote is attributed to Seamus Heaney.

Technique is the outward sign of an inner conviction. - Seamus Heaney

"Technique is the outward sign of an inner conviction."

Seamus Heaney Work

Poet Irish 1939–2013

"Between my finger and my thumb the squat pen rests; snug as a gun."

"Whatever is given can be taken away."

"The main thing is to get the mood right."

"Happiness, I have discovered, is nearly always a rebound from hard work."

"Hard work never killed anybody."

"Work with purpose and integrity."

"Hard work pays off in the end."

"A man's gotta do what a man's gotta do."