1 pointTo exist at all is to act, "act" in the ordinary active sense not a contrived passive sense. A table which holds up a glass is acting in accord with Newton's Third Law of Motion (for every action there is an equal and opposite reaction) as applied to static entities. Analyzing the same table-and-glass with the latest state-of-the-art physics does not change the conclusion that there are multiple entities acting and interacting as their attributes dictate.. A passive sense of action attributed to merely existing is an empty concept because it cannot refer to anything which is solely inherent to existing. Any possible candidate referent of such a concept would have to be an attribute that necessarily interacted with other entities before we could become aware of it. To return to Rand's short style phrases, "Existence is Identity" strictly contradicts "Existence has Identity".
1 pointEasy Truth, welcome to Objectivism Online. I liked Aristotle’s bit about truth being in one way hard and in another way easy, “like the proverbial door one cannot avoid bumping into.” Your insight that if existing were itself an action, it would imply that all entities act is right, provided we keep constant the sort of action we are talking about throughout that if-then statement. That kind of action would be something more inert than when, in science or in everyday experience, we say that such-and-such thing acted in such-and-such way. Nevertheless, for those who love not only easy truth, but hard truth, the question of whether existing is itself an action, or activity, is a good one. Aristotle, Leibniz, and Lotze affirmed. Russell denied, arguing against Lotze. The case that Aristotle is an affirmer on this question is made out by Aryeh Kosman in his book The Activity of Being (2013). I’m a denier on the conception of existing as necessarily being a sort of acting. I affirm that all concrete existence is temporal, but for that, it suffices that some concrete part in the whole of concrete existence is acting in our ordinary and scientific types of acting. To be clear, I’m talking about any sort of acting that has been connected in a necessary way with existence per se in the history of philosophic reflection or is thusly connected by us in our philosophic reflection today. What we know from science (e.g. that mass is convertible to energy, that mass-energy has some dynamical relations with spacetime, and that the vacuum has energy) concerns other sorts of activity than the one that has been claimed by philosophers for existence per se, and these activities we learn in the physical sciences were conceived and discovered by means necessarily beyond philosophic reflection.
1 pointOf related interest is a remark of Harry Binswanger in his 2014 book: “When one billiard ball collides with another and sets it in motion, the interaction is causally determined by the nature of the entities involved, including their state of motion” (HWK 347–48). By state of motion, he means such things as velocity and spin. It is odd to regard such things as part of the nature of a thing. To be sure, it is part of the nature of a thing to be possible for it to have or not to have such states and, if so, in certain possible ranges of magnitudes of those states (magnitudes of spin, magnitudes of linear velocity). But the actual values of those traits at hand are attributes, and removable ones, not natures of the billiard balls. That is not to say that all actual attributes of entities are not part of what we ordinarily mean by natures of the entities. The elasticity of the balls, an attribute whose magnitude is invariant for ordinary billiard balls, is more aptly called part the balls’ nature in the collision.