The Causal Link
Published: April 12, 2009

One of the most important concepts in science is the causal link. The word causal simply means of, involving, or constituting a cause. The word link simply means a relationship. An excellent explanation of the causal link is given to us by the Canadian philosopher Leonard Peikoff. He explains that:

“the causal link relates an entity and its action. The law of causality does not state that every entity has a cause. Some of the things commonly referred to as “entities” do not come into being or pass away, but are eternal – e.g., the universe as a whole. The concept of “cause” is inapplicable to the universe; by definition, there is nothing outside the totality to act as a cause. The universe simply is; it is an irreducible primary. An entity may be said to have a cause only if it is the kind of entity that is noneternal; and then what one actually explains causally is a process, the fact of its coming into being or another thing’s passing away. Action is the crux of the law of cause and effect: it is action that is caused – by entities.

By the same token, the causal link does not relate two actions. Since the Renaissance, it has been common for philosophers to speak as though actions directly cause other actions, bypassing entities altogether. For example, the motion of one billard ball striking a second is commonly said to be the cause of the motion of the second, the implication being that we dispense with the balls; motions by themselves become the cause of other motion. This idea is senseless. Motions do not act, they are actions. It is entities which act -, and cause. Speaking literally, it is not the motion of a billiard ball which produces effects; it is the billiard ball, the entity, which does so by a certain means. If one doubts this, one need merely substitute an egg or soap bubble with the same velocity for the billiard ball; the effects will be quite different.

The law of causality states that entities are the cause of actions – not that every entity, of whatever sort, has a cause, but that every action does; and not that the cause of action is entities.”1

When I read Peikoff’s explanation of causal link, I realized that if he had used the words “atom” and “atoms” instead of the words “entity” and “entities,” his explanation would be an explicit Atomic explanation.

It is important to understand that atoms are the only entities in the universe. They are eternal and indestructible, and they give permanence to the universe. No cause can be given for their existence, which makes them irreducible primaries.

When we talk about noneternal things, we are talking about the things whose existence have been caused by the aggregation of atoms.

As The Theory of Atomism explains, the gravitational interaction of the eternal and indestructible atoms ultimately causes all the different phenomena in nature. We cannot bypass the atoms and explain their actions, or energies, as being things that exist separately from them. Nothing exists but atoms and the void, which has no power to affect the atoms and aggregates of atoms moving within it.

Modern theoretical physicists, who are not Atomists, talk about the energies of atoms - heat, light, sound, etc. - as though they are things that exist separately from atoms and have the ability to do work. The energies of atoms do not act, they are actions of atoms. In other words, it is atoms which act and cause and produce effects. Let it be clearly understood that the energies of atoms and aggregates of atoms are not things; they are activities, or actions, of things made up of atoms.

Here, it comes to my mind that Max Planck’s Quantum Theory claims that hot objects give off energy, or heat, in a stream of separate units called quanta. This is simply not true, because objects are not made up of energy but atoms. Objects can only give off constituent atoms. I will reiterate that energy is the name given to activity, or action, of atoms. It cannot be separated from atoms and given off as units of quanta, or immaterial heat.

Modern theoretical physicists often relate heat to motion of molecules. The motion of molecules does not act, the motion of the molecules is action of the molecules. It is not the motion of molecules which produces heat; it is the molecules, the particles, which do so by means of certain kind of motion. We may end this discourse on the causal link with the understanding that the cause of all action, or activity, in the universe is the eternal and indestructible atoms of which everything in the universe is made. The causal link relates atoms and their actions.



  1. From- OBJECTIVISM: THE PHILOSOPHY OF AYN RAND by Leonard Peikoff, copyright (c) 1991 by Leonard Peikoff. Used by permission of Dutton signet, a division of Penguin group (USA) Inc. *Disclaimer: Mr. Peikoff has no knowledge of the other content of, nor is he affiliated with, this website.