“Clinging to life affects even the wise; it is an inherent tendency”
--The Yoga sūtras of Patañjali, II.9
In this blog post, I am going to discuss a couple interesting philosophical concepts from Indic (Jain, Buddhist, and Hindu) traditions in the context of evolutionary biology. These concepts are samsara and samkaras, which I think are highly relevant to understanding the human experience, no matter whether one believes in a deity or not.
All living beings fear death from the moment they are born. In the Yoga school of Indian philosophy, this observation supports belief in samsara, the unending cycle of birth, death, and rebirth. Vyasa, legendary sage and traditional commentator, makes the following argument: the fact that all beings wish to live forever suggests that they have experienced death in the past. Therefore, one can conclude that every being has experienced previous births (Bryant 2009).
Do we have memories from past lives? I think a better term than memory is samskara, which refers to a mental impression or psychological imprint that affects our behavior and disposition. Samskara is more general than just remembered experiences in our lives, because it also refers to unconscious conditioning due to how other people treat us as well as our own actions. Samskaras also refer to imprints from past lives.
Here’s an obvious scientific problem: what physical mechanism underpins how samskaras propagate across births? My answer to this question is that there are at least three physical mechanisms that transmit samskaras across births: our genetic, epigenetic, and cultural inheritance. Do we also need to keep track of how souls transmigrate between bodies? My answer to this second question is no—one does not need to believe in (or deny) the existence of a soul that passes sequentially through bodies for samsara and samskaras to make sense.
I’ve avoided the English word “reincarnation” because this word implies the existence of an eternal soul that is passed along from generation to generation in new physical bodies, while samsara refers to endless birth, death, and rebirth among living beings. Many religious and philosophical systems assume the existence of eternal souls as an axiom, while other belief systems reject the existence of eternal souls. The discussion here does not hinge on the question of whether or not souls exist.
In a sense, Darwinian evolution is one description of samsara, the cycle of birth, death, and rebirth. Darwinian evolution describes how populations change over time, and it is natural consequence of three observations. First, all living beings are born, they reproduce, and they die. Second, all living beings resemble their parents, and leave offspring that in turn resemble them. Third, occasional errors are unavoidable in any replicative process, whether copying a text or copying genetic information encoded in genomes.
The second observation implies that all living beings carry genetic information: information passed on from generation to generation that describes how our bodies develop and survive. The third observation, that perfect replication fidelity is physically impossible, implies that there is always some variation in populations. If there is variation in the ability to survive and reproduce among individuals, then over time the individuals best able to survive and reproduce will leave more descendants, and the population will change due to this process of natural selection.
Our genes have been inherited over billions of generations—in a very real sense, our bodies physically carry information about how to best survive in the world and leave offspring behind. Conflict and suffering are inherent to life because Darwinian evolution boils down to innumerable cycles of birth and death. While Darwinian evolution describes samsara, it is only one of several mechanisms that transmit samskaras.
The experiences of our parents affect the way our bodies develop and function. One physical mechanism is called epigenetic inheritance. For example, the experiences that our mothers go through while we are in the womb affect our development, and there is a growing body of research into maternal effects in development. One research study into maternal effects showed that stressed squirrel mothers have babies that grow up faster compared to the babies of unstressed mothers. But what is truly alarming is that we are now exposed to a morass of poorly studied environmental toxins in our everyday lives, causing health effects that will linger for generations.
We also inherit the cultural baggage of past generations. The legacy of slavery and white supremacy still lingers in American society, as the recent murders in Charleston remind us. It’s easy to scapegoat the Confederate flag and the South (as the media is doing) while forgetting that the slave trade was the basis of the pre-industrial New England economy, that Oregon banned black people until 1927, and that Chinese were banned from immigrating to the USA from 1882 till 1943. We don’t have to remember the past for it to affect us.
We have inherited many samskaras from past lives. Our genetic, epigenetic, and cultural inheritance are three ways in which samskaras from past lives become imprinted on our bodies—even before the moment of our birth.
Reference: Bryant, E. (2009). The Yoga sūtras of Patañjali: A new edition, translation, and commentary with insights from the traditional commentators. New York: North Point Press.