Time in physics is a linear mathematical variable used to express the measurement of one motion as the comparison of it to another motion. Time equals zero is usually assigned arbitrarily. A good example is the temporal count down to the launch of a rocket which is negative, with the launch expressed as zero and post-launch as positive.
In consideration of measurements of the expansion of the universe, the mathematical variable, time, may be expressed in regression to zero. In accord with this regression, the universe regresses to a point source of energy. In accord with this beginning of the universe, this beginning of mathematical time, the philosopher, William Lane Craig, lists the work of the mathematicians and physicists, Einstein, Friedmann, Lemaître, Hubble, Borde, Guth and Vilenkin.
Craig proposed a syllogism, based on this mathematical beginning of the universe, as the Kalam cosmological argument for the existence of God:
Major: Whatever begins to exist has a cause.
Minor: The universe began to exist.
Conclusion: Therefore, the universe has a cause.
The syllogism in greater detail is this:
Major: An entity, which begins to exist, cannot explain its own existence, which must be explained by another entity that does explain its own existence.
Minor: The motion of the universe, which is measurably expanding, may be viewed in reverse as a regression of the mathematical variable, time, to absolute zero, with the universe regressing to a point of pure energy. The universe began to exist at time, zero.
Conclusion: Therefore, the existence of the universe, as an entity, must be explained by another entity, which explains its own existence.
Craig also presents another argument in justification of his minor premise, ‘The universe began to exist.’ According to the second law of thermodynamics, a closed system moves to thermodynamic equilibrium, or as expressed by Craig, ‘a closed system runs out of energy.’ Craig argues that if the universe existed ‘forever’ it would by now have run out of energy, therefore it had a beginning. To me that is not really the argument proposed. This is: The universe is a closed thermodynamic system, which had a beginning. Its beginning, as a closed system, was not too long ago, because the universe has not yet reached equilibrium. This second argument does not justify, but assumes the minor premise. The first argument, i.e. the regression of time to zero, justifies the minor premise.
The fact that the minor premise is scientific, excludes almost everyone from recognizing its validity directly. Most would accept it as true on the authority of the scientists, who testify to it on the basis of instrumental measurements and of the mathematics, letting the variable, time, regress to zero. Consequently, the syllogism, even if technically valid, would not be a convincing philosophical argument, because it is based on authority.
The main logical problem with Craig’s argument is the mixing of science and philosophy. The major premise and the conclusion are philosophical, while the minor premise is scientific. Science is the determination of the mathematical relationships inherent in the measurements of the properties of material reality. Philosophy is the study of things in their essences, i.e. in their non-measurable fundamental natures, and in their existence.
A good example for the sake of differentiating science from philosophy is the concept of time. In philosophy, time is that characteristic of material things which subjects them to change. In science, time is the measured comparison of one motion with another motion. For example the flight of an airliner from one city to another might equal one twenty-fourth of the full rotation of the earth on its axis.
Philosophically time is a condition, a quality, namely that of being subject to change. Philosophical time is not extended. It is the non-extended, the non-measurable now of mutability. The past is a qualitative distinction. The future is a qualitative conjecture.
Scientifically and in common parlance, time is a mental comparison. It is the measurement of one motion by comparison of it to another motion. Mathematically it can be represented by a quantitative variable. As measurable, scientific time gives the illusion of extension in the sense of extension characteristic of any Cartesian, algebraic variable.
Trent Horn presents a justification of the minor premise of the Kalam cosmological argument which does not depend upon science (p 126, Answering Atheism). Instead he presents a variation of Zeno’s argument that time cannot be actualized by the summation of infinitesimal increments. Zeno concluded that motion must therefore be an illusion. Horn argues that the universe had to have had a beginning because an infinite time cannot be actualized by the summation of finite increments. Horn’s argument would be valid, if time, as a mathematical variable characterized by Cartesian extension were, as such, an actual characteristic of reality. It is not. Time, as a mathematical variable or an increment of such a variable, is purely logical. As such it is a human concept, not an actuality. No logical analysis of logical concepts, no mathematical argument, can reach a conclusion involving existence.
Can the Kalam minor premise be understood philosophically, rather than scientifically or mathematically? Excluding the scientific and mathematical interpretations of it, reconsider the minor premise, ‘The universe had a beginning.’ In other words, can the universe be said philosophically to have had a beginning? The universe is not a philosophical entity. It does not exist as a being. Rather the universe is the conceptual set of all material beings. As philosophical, the claim that ‘the universe had a beginning’ implies that the universe is both an entity in itself and an entity humanly knowable as an entity in itself.
No one claims that the universe is now an entity in itself. No human has even sense knowledge of the universe as a thing. The universe, as the set of material things, is an abstract concept, not an entity of human experience and knowledge. However, the minor premise of the Kalam argument requires that the universe is an entity in itself. For logical validity, the universe cannot be understood analogically as an entity. For the logical validity of the syllogism, the universe must be an entity in itself.
In general, an argument for the existence of God, which is focused on the universe, is invalid. The universe, the totality of material reality, is not within the scope of human experience. It is not an entity, i.e. a nature in possession of existence. The universe, as the universe, is fundamentally a human concept. To say that this dog exists or came into existence is an ontological statement. It is a statement about being and about a being, an entity. To say that the universe exists is not a statement about a being, about an entity. In contrast to the statement about this dog, the statement about the existence of the universe is merely analogically about an entity. Consequently, it is not possible to draw a fundamental conclusion about being based on a premise involving the existence of the universe, which is a philosophical non-entity. In my judgment it is not possible to determine from philosophy whether or not the universe had a beginning. And, of course, existence is not measureable and is therefore not within the scope of scientific scrutiny.
Would not the currently accepted scientific consensus of an energy point source of the universe philosophically identify the universe in its origin as an entity in itself? This conjecture would imply that the universe is still a single entity. It would imply that all subsequent differentiation of the initial being, energy, is simply that, the differentiation of a single being. In other words, even humans are phenomena whose entire spectrum of knowledge is simply phenomena. Every differentiation, including humans, is an incidental aspect of a single being, the energy, which is the universe. After all, according to Craig, the universe is a closed system since its beginning.
The Kalam cosmological argument fails as a proof of the existence of God.
(1) Only an entity can truly possess existence, come into being, begin to exist. The universe is not an entity in itself.
(2) Conclusions regarding existence can only flow from premises based on direct human experience of existing entities. The universe, as the universe, is not within the scope of human experience.
(3) In contrast to conceptual time, real time, which is the qualitative now of mutability, lacks extension, including the conceptual extension of an algebraic, Cartesian variable.
(4) The validity of the mathematical equations representing the measurable properties of things does “not imbue mathematics with the ability to impart ontological status.” (See the video of the Science and Faith Conference in 2011, at 1:05.)
(5) Space and time are not realities, but mathematical conceptualizations. The human, mental concepts of space and time correspond analogically to the relational location and to the relational motion of material things, respectively.
For an essay on St. Thomas’ five ways of proving the existence of God see my essay here.