4 If, again, the Æons were derived from Logos, Logos from Nous, and Nous from Bythus, just as lights are kindled from a light— as, for example, torches are from a torch— then they may no doubt differ in generation and size from one another; but since they are of the same substance with the Author of their production, they must either all remain for ever impassible, or their Father Himself must participate in passion. For the torch which has been kindled subsequently cannot be possessed of a different kind of light from that which preceded it.
Wherefore also their lights, when blended in one, return to the original identity, since that one light is then formed which has existed even from the beginning. But we cannot speak, with respect to light itself, of some part being more recent in its origin, and another being more ancient (for the whole is but one light); nor can we so speak even in regard to those torches which have received the light (for these are all contemporary as respects their material substance, for the substance of torches is one and the same), but simply as to [the time of] its being kindled, since one was lighted a little while ago, and another has just now been kindled.
Source: Adversus haereses (New Advent)