What is the meaning of life? The short answer, there is none. There is, however, a deep reason for this answer that has to do with the conflict between how the universe operates as a whole, on the one hand, and how we naturally view reality, on the other. This leads to two questions. First, what is the nature of this conflict? Secondly, why does it exist? Once these questions are addressed, the reason for the short answer to the meaning of life becomes apparent for we shall see that life as a whole has no purpose and without purpose it does not have meaning.
Let’s begin with space and time. What the best investigation into the nature of space and time has revealed is counter-intuitive in two ways. First, it turns out that space and time are in fact aspects of a four-dimensional manifold and it is this whole that has physical significance. What this means is that its components, space on its own and time on its own, are derivate parameters and may vary so long as they add up in such a way as to preserve the properties of the whole, space-time. For example, for different observers, four-dimensional space-time will break down differently so that, between two events, more time passes for one than for the other. This is not just an effect of perspective but, rather, a mathematical consequence of how space and time jointly compose space-time, which manifests itself physically in, for example, the slowing of clocks that move at high velocities relative to the surface of the Earth, such as satellites.
Secondly, the formulas that describe space and time are simply expressions of conserved or covariant quantities that are devoid of reference to any purpose for their being what they are. They are non-intentional descriptions of natural structure. For example, in the case of four-dimensional space-time, we have Einstein’s Field Equations,
relating the distribution of matter (right-hand side) to the curvature and metrical properties of space-time (left). This is a descriptive equation and holds universally and independently of any consideration of purpose; it will not, for example, license the bending space-time specifically in order to aid or thwart our goals or plans.
Similar considerations hold with regard the equations of quantum physics, such as the Schrodinger equation,
which relates the rate of change (right-hand side) of a material system to the energy of the system (left-hand side). This holds universally and makes no exceptions on the basis of human goals or purposes; for example, the justness of a cause will not impact whether or not matter behaves in accordance with this equation.
It is important to note that the process that led to the existence of all life on the planet, i.e., evolution through natural selection, is similarly non-intentional and non-teleological. For evolution through natural selection to occur, three elements are required: variation, filtration, and replication. Variation in traits leads to differences in fitness relative to a local ecological niche, resulting in differential success in achieving reproductive maturity. If success-enhancing traits are propagated in the reproductive process, they will, over time, arise to prevalence within the population, so long as the ecological niche remains relatively stable (if not, then the organism may go extinct). Though the term can be used innocently enough, there isn’t really any selection here, just differential reproductive impact of traits given the local environment. It may appear as though a kind of creature is being fine-tuned for its surroundings, or that the two were pre-planned for each other, but nothing of the sort needs to be assumed in order to explain the rise and fall of different biological features so, accordingly, such an assumption adds nothing of scientific value to the explanation of what we observe. Variation, random or otherwise, differential reproductive success, and inheritance of traits, all occurring without an eye toward the future, will lead over time to biological adjustments better suited to the local niche. Natural selection is not, in other words, toward anything, or in the business of identifying and achieving goals.
So, nature operates non-intentionally, free of goal or purpose. Why, then, do we find it natural if not inevitable to interpret the world teleologically? Why would someone such as Aristotle find it compelling to view all of nature, including the motion of inanimate objects, in goal-oriented terms?
The answer strikes me as having to do with the pressures faced by relatively small and weak hominids in a hostile environment. Unlike a rock, which persists without the need for any input of energy, or a star, which has a large, internal store of energy, an animal’s survival depends on finding, securing, and ingesting external sources of energy. In order to persist, therefore, an animal must seek and secure resources in its niche. Animals able to do so reliably will endure; those unable to do so will perish. The required resources need not be plentiful or easy to come by, just sufficient to be attainable on a regular basis via non-fatal effort. That’s it. Life needn’t be easy, in other words, in order to persist and multiply; it can be mostly suffering and still be biologically well adapted to its environment.
So, living creatures, unlike the matter composing them, need to be goal-directed, regularly on the lookout for sources of energy, ready to pounce. It is, further, of significant help to be able to plan for the future and to anticipate; given the scarcity of resources, any skill in plotting for future success is an advantage. It is unlikely, therefore, that our ancestors would have survived for millennia in hostile environments had they taken a nonchalant or indifferent attitude toward such things as securing food, shelter, and mates. Without forming goals, human beings would lack the motivation to act in the ways required for their survival. A rock just sits there, doing nothing, unless moved by something else. The Sun just moves along its orbit burning away its nuclear energy, which it will continue to do until it is a cold, spent remnant of its former self, and it will not alter its trajectory in search of nuclear fuel; will not set off into other solar systems in order to feed itself. The Sun, in short, has no goals.
The Sun can persist for billions of years without forming goals, as can a rock. Human beings are not so lucky. If we were to simply sit still, unmoved except by external forces, then we would starve to death well before producing offspring, and the species would disappear in less than a generation. No animal can persist that lacks internal motivation, without which it will not so much as move unless rolled by an avalanche or tossed by a wave. The only way for our ancestors to survive was to seek and pursue with regularity. Accordingly, we evolved to see reality in terms of goals. We must set goals, form plans, and then act upon them.
We must, however, do more than attend to our own goals, because we are, individually, relatively weak creatures. Accordingly, we are required to work with others in order to succeed. This means we must plan and coordinate our activities with other people who are attending to their own goals and forming their own plans as a result. In short, it is essential for us to detect and pay attention to the goals of others as well as our own, for otherwise coordinated action would be unwieldy if not impossible. So, it should be no surprise that we evolved to be rather sensitive to goals and plans, whether in ourselves or others, and constantly look out for them in order to coordinate our actions. It should, further, be no surprise that we formed a tendency to overgeneralize here. Not only did our survival depend on tracking and hunting animals, who act in their own goal-oriented ways, but there was no way for the process of natural selection to know in advance where in nature goal-directed behaviour would end and mechanical behaviour would begin. It would be better to err on the side of seeing purpose where there is none rather than the reverse, for in the latter case we may become insensitive to our fellow strugglers on whose cooperation our lives depend; attributing goals and desires to rocks and stars will produce false theories but failing to work with others is often fatal.
In sum, because we want to survive and need scarce things to do so, we evolved to be oriented to reality through the lens of goals and plans, i.e., purpose. We must form and attend to our own goals and, because we are relatively weak, we must work with others to achieve our joint goals; hence, we must also be sensitive to the goals of others. Finally, since the non-intentional process of evolution cannot predict where goal-oriented activity itself will and will not evolve in the future, a bit of oversensitivity is a good bet, which means we will generalize and look for goal-like behaviour throughout nature, as did Aristotle in his physics and cosmology.
The problem, however, is that we now know from scientific investigation that nature itself is not best viewed in this way. Evolution itself is non-teleological and non-intentional, as are the physical laws that govern space-time, matter, and energy. In short, the concepts of goal and purpose only make sense from within, i.e., relative to the viewpoint of human beings; they simply do not apply to reality as a whole. While we know that human beings have goals and form purposeful behaviour as a result, the nature within which we behave has no overarching goal or purpose. It would be an instance of the fallacy of composition to assume that because entities within the world have goals, so does the world itself. In relation to living beings, there exist goals in nature; otherwise, there do not.
Is an apple food? It is for us, and some other animals, but not for a rock or the Sun. Accordingly, ‘is Food’ is not a property of the apple; rather, ‘is Food for x’ is. On its own, intrinsically, the apple is not food; the property is a relational one. Why, then, do we eat apples? Because our survival depends on calories, and they have them. But note that this is an incomplete answer. We need to add, ‘and we seek that which aids our own survival’; otherwise, we might just sit around uncaring or waiting for an apple to fall in our mouths. By comparison, as noted above, though the Sun needs hydrogen for fuel, and there is hydrogen throughout the galaxy, it will not travel from system to system in search of hydrogen when it begins to run dry. We seek what we need to survive because we want to continue living, but if we remove that desire then the apple remains a source of energy but not a kind of food. It becomes something that exists but is not part of any purpose. Purpose is relative to wants and needs, so it is internal to the human perspective. What this means is that our lives as a whole lack a goal or purpose because it is only relative to being a lifeform that goals exist. Asking for the goal or purpose of life makes no sense because ‘goal/purpose’ is defined relative to life and presupposes it. By analogy, we can ask for the angle between two lines in space but not the angle of the space itself; or, while one person may be younger than another, the pair itself is neither younger nor older than anyone.
Whether or not the foregoing evolutionary speculation is correct, it is undeniable that we see the world in terms of goals and purposes, which means our cognitive orientation is ill-fitted to understanding nature as a whole, though we can overcome this difficulty with good scientific theories. Hence, the question we ask of reality, ‘what is the purpose of all this?’, is ill-suited to be answered by it because reality has no goal or purpose. One can have a meaningful life in the sense of a life filled with goals that are pursued and fulfilled, but this does not entail that there is any purpose of, or to, the whole process itself. On the assumption that meaning entails purpose, life can have no meaning.
This answer helps explain why I write, in the title, that life probably has no meaning. My answer leaves room for doubt because it depends on taking the scientific conception of reality seriously and it is possible, if unlikely, that this picture is false. Perhaps the universe was created with a purpose by an intentional being. Perhaps we were created with a specific purpose in mind by an intentional being who inhabits a purposeless universe (e.g., the simulation hypothesis). The religious worldview is in deep tension with the scientific but not, strictly speaking, incompatible with it. While I find the scientific worldview compelling it is, like all theories within that worldview, subject to revision should evidence against it arise. I think, however, that in the absence of some kind of intentional creator or the overthrow of modern science, the question as to the purpose of life makes no sense.