a Some Bibles use the word “world” instead of “system of things.” W. E. Vine’s Expository Dictionary of New Testament Words says that the Greek word ai·onʹ “signifies a period of indefinite duration, or time viewed in relation to what takes place in the period.” Parkhurst’s Greek and English Lexicon to the New Testament (page 17) includes the expression “this system of things” in discussing the use of ai·oʹnes (plural) at Hebrews 1:2. So the rendering “system of things” is in harmony with the original Greek text.