I recently came across the article Buddhism and the Brain, in which the author (Dr. David Weisman – a Neurologist but not a Buddhist) discusses the significant overlap between ancient Buddhist understandings of the mind and our best modern understandings of Neuroscience.  In fact, the overlap between Buddhism and science is not limited to just the realm of the brain.  There are numerous parallels to Buddhism in the modern fields of cosmology and particle physics as well (for a deeper dive, I highly recommend the Dalai Lama’s book The Universe in a Single Atom).  Dr. Weisman’s conclusion (with which I agree) is that the founders of Buddhism were fundamentally empiricists – they started with no preconceptions about how the world should work, but instead studied how it does work with an open mind and a willingness to be proven wrong.

The one place in which I disagree with Dr. Weisman’s article is in his hope that Buddhists will “allow neuroscience to render their idea of reincarnation obsolete.”  The idea of reincarnation within Buddhism solves two fundamental human needs which science has not yet (and may never) be able to solve.  The first, and most obvious, is the fear of death and the question of “where do we go after we die?”  Science’s answer of “nowhere, you just cease to be” is unsatisfying to many (though not all) people.

The second need is less obvious, but much more problematic.  This is the issue of “free will.”  In a purely scientific understanding of the brain, there is no mechanism for free will.  Our brains are entirely composed of atoms and molecules which obey the well-understood laws of chemistry and physics.  Whether or not a single neuron fires is solely determined by the chemical and electrical inputs it receives.  Although the combination of billions of these neurons acting in concert is far too complex for us to trace every possible pathway, in a deterministic universe, the behavior of every one of these pathways is entirely determined by the inputs it receives.  Therefore, the brain as a whole operates in an entirely deterministic way based solely on the external factors operating on it from the environment.

With the advent of quantum mechanics, we now understand that the brain isn’t truly deterministic because of the probabilistic nature of quantum fluctuations within atoms.  However, this just means that the actions of our brains (and thus the decisions we make) are a combination of deterministic and random.  This still leaves no place for “free will” which has led some to conclude that free will does not actually exist and is merely an “illusion.”

The issue of needing free will is more fundamental than just satisfying people’s own personal belief that they have it.  All societies are based on the principles of personal choice and responsibility.  If free will is merely an illusion and does not actually exist, then we can no more praise Nelson Mandela or Mahatma Gandhi than we can vilify Adolf Hitler, Joseph Stalin or Pol Pot.  Nobody can be said to be “responsible” for their actions – they are merely reacting to external forces.

The Buddhist concept of Vijñāna can solve the problem of free will while coexisting nicely with all of our modern understandings of the brain, chemistry and physics.  The brain can be understood to follow all of the basic laws of science, but the Vijñāna exerts an undetectable influence over our brains which skews the quantum mechanical fluctuations of particles so that they are not purely random, but instead act in concert to influence our decisions and actions in a non-random way.

Unless, or until, science is able to explain the existence of free will (or to answer the question of how can we hold people responsible for their actions in the absence of free will), then there will always be a place for the “idea of reincarnation” within Buddhism.