Where Did Life Come From? The Mind? The Universe? Can We Even Know?
Today I'd like to start a discussion on the ways certain kinds of questions present formidable challenges to the conventional scientific method of explanation, based on hypotheses and empirical validation. Given that the topic is vast and space short, I will divide the discussion into three parts (at least). Although there may be many questions that pose a challenge to the scientific method (for example, the much-debated questions of morality and altruism), I am interested in a trio that can be grouped as the "three origins questions": cosmos, life, and mind.
Working with any of these can fill many lifetimes of research, without any promise of success. In fact, how we measure success in answering any of these questions is already part of the challenge. They each invoke different areas of research, with different operational principles and scientific methodologies. Even so, there are points in common, and it is to those that I turn today, and in subsequent blog posts. (There have been many books and essays written on these three issues, taken together or separately. At the end I provide a list of further reading.)
The first point in common is that not so long ago these three questions were not considered scientific. On the contrary, the origin of the Universe, of life, and of mind were thought to be the result of divine work, products of supernatural intervention. Which god or gods were responsible depended (and still does to the vast majority of the world population) on your particular faith. Differences aside, in any religion only an entity that transcended space and time could create the cosmos, which exists within space and time; only an immortal entity had the power to create life; and only an omniscient power could endow His creatures with intelligence and a sense of being.
The confrontation with natural processes is immediate: Nature is within space and time, living entities are not immortal and no one is — or can be — omniscient. (Although the World Wide Web, allied with global human intelligence and powerful search engines, could, in some sense, be called a proto-omniscient entity. Stuff for another week.)
For this reason, it is not at all surprising that scientists encounter such resistance when they state that they are near — or at least making progress — in answering such questions without recourse to divine intervention. According to the scientific viewpoint, the origins of the cosmos, of life and of mind are natural processes that obey material laws and principles. Their complexity and our current lack of answers do not mean that such questions are completely beyond the reach of science, or that such questions can only be addressed through religious belief. In science, ignorance is the pre-condition to knowledge; to not-know is the pathway to knowing.
Perhaps the proper way to phrase the question is not whether science can provide answers to the three origins but how far it can go in answering them. For it may very well be that science can only go part of the way. To see why, let's begin with the one that may, perhaps, be the "easiest" of the three, the origin of life.
Although we are far from understanding the details (see guest blogger Wim Hordijk's recent contribution to these pages), it seems clear that the transition from non-life to life follows from the increasingly complex chemical reactions that took place on primal Earth: at a certain point, networks of chemical reactions became self-sufficient and, partially isolated within protective membranes, were able to absorb energy from the outside environment and to produce copies of themselves with some efficiency. We certainly don't know how this happened here some 3.5 billion years ago (or even earlier).
More to the point, unless someone offers a formal proof that there is only one biochemical pathway toward life — a possibility that I consider highly unlikely — we will never be able to know exactly how life emerged here. At best, we can come up with viable scenarios of the origin of life given the conditions prevalent on primal Earth (another challenge in itself, to find those out).
So, the question of the origin of life, at least in the exact way (or ways, for it may have happened more than once) in which it emerged here or in any other planetary platform out there, is not answerable scientifically. Does this mean that science can't help us understand the origin of life? Not at all. We can only understand the origin of life through science, even if this understanding is necessarily limited. Of the three origins questions, the origin of life is still the most tractable, given that we can simulate conditions and chemical reactions in the laboratory with some degree of control.
Contrary to the origin of the Universe or of mind, the origin of life is a problem we can attack from the outside in. It is for this reason that I call it the "easiest" of the three, although there is nothing easy about it.
Molecular biologists like Gerald Joyce, from the Scripps Research Institute in La Jolla, and Nobel laureate Jack Szostak from Harvard University, among many others, are making spectacular advances toward understanding life. They can manipulate RNA and DNA and coax them into enacting the game of life, that is, respond and adapt to environmental pressure as the theory of evolution dictates; they can strip away cellular structures and genes from living cells to search for the minimum living system; Günter von Kiedrowski in Germany was able to construct auto-catalytic chemical sets that show self-replicating abilities.
These experiments are not yet creating life in the laboratory. But they are certainly steps in the right direction. Even if we will not be able to explain exactly how life emerged on Earth, science still offers the only pathway toward understanding.
A Short Reading List On The Three Origins:
The Origin of the Universe, by John Barrow
Big Bang: The Origin of the Universe, by Simon Singh
A Universe From Nothing: Why There Is Something Rather Than Nothing, by Lawrence Krauss
The First Three Minutes: A Modern View of the Origin of the Universe, by Steven Weinberg
The Dancing Universe: From Creation Myths to the Big Bang, by Marcelo Gleiser
Origins of Life, by Freeman Dyson
Seven Clues to the Origin of Life: A Scientific Detective Story, by A. G. Cairns-Smith
The Fifth Miracle: The Search for the Origin and Meaning of Life, by Paul Davies
Life's Origin: The Beginnings of Biological Evolution, J. William Schopf, ed.
Origin of Mind: Evolution of Brain, Cognition, and General Intelligence, by David C. Geary
Astonishing Hypothesis: The Scientific Search for the Soul, by Francis Crick
How the Mind Works, by Steven Pinker
Self Comes to Mind: Constructing the Conscious Brain, by Antonio Damasio