Is it more accurate to think of reincarnation as sequential in terms of human perception of time, or is it more accurate to think of it as occurring in terms of life lessons. For example, say if someone is working on a lesson that takes them from a life lived in the thirties to one lived in the dark ages?

This is a very astute and perceptive question, and we would answer it as in the affirmative. The importance of human lives stems from their growth potential to offer lessons and learning about spiritual growth and progression, in the most trying of circumstances. The act of incarnation puts humans in the line of fire. They are truly entering a battle zone, a contest for supremacy between the light and the dark. If they make a misstep they will be caught into a swirl of negative karmic events and then as a consequence must pay their dues to right the wrongs and to rebalance things. This is the imperative that stems from all action of humans in the physical. So the link between lives is not sequential in a chronological sense, but sequential in a karmic sense. So the task of a current life may very well be the continuation of a drama from a lifetime back in history, maybe even many lifetimes ago, and is only now picking up that thread. So it is common after a life of great trauma for a light being to reincarnate and have a timeout, a time of relative rest, and a sojourn here doing light work to be sure, but light work So many who currently have lives that seem unruffled, who seem to have a charmed existence with many pleasures and benefits and successes as one big happy family of successful, accomplished children, and recognition among the community as being a pillar and contributor, and living goodness and rich existences, these are often timeout lives and they serve the person by regaining their footing and growing in other ways, mainly as serving others as examples and as accruing more positive karma because of their achievements and accomplishments, and regaining their ability to connect to earth energy without overwhelm. Many times when there is a crib death, for example, it results because someone is re-entering Earth with a huge karmic dilemma in recent experience. And the re-emergence in Earth plane stirs this up and causes tremendous fear and the soul will want to leave, and then they may well do so. The purpose of spreading things out a bit is not to avoid the responsibility to pay back or rebalance, but to do it in a planful way. So the question is spot on and metaphysically astute in this regard.