Action is so pregnant. I write, think, sit, reflect, way, type, scan, focus, marshall, ignore, embrace. I act. Action is not possible to understand without ends, means, values, preferences, choice. Now we add time. Action is always in time. As usual I make an effort to avoid metaphysics (Presentism vs. Eternalism about time) and focus on what action is and what it requires. The consideration here is abstract but in the interest of moving toward completeness worth making.
To act is to attempt to employ means to reach ends. It is to cause. The agent acting always wishes to bring about some effect. It is impossible to act without the framework of cause and effect, and this is a framework that is necessarily temporal. It is that there is a future which it is conceived may or may not contain the effect desired and that it is related (mistakes possible) to these means and the employment of resources in this way which are present that I find it worth acting.
Were there no causal framework embedded in a necessarily temporal order I could not act. Imagine, per impossible, a timeless present. It would be a place of no change. Is is not imaginable. Change, the category in which human action falls, is necessarily temporal. There is before and after. They are sequentially related. Simultaneity is impossible. It is inconceivable.
In action some portion of the present is traded for some hope in the future. The investment that is made is always in time and conceived in time. Were there no categories of the future and present there would be no category of action. And were that temporal order not conceived as an order in which there are time-invariant causes, that is things that have effects given their causes and regardless of the particular time, action would be impossible.
We may not be able to prove positively that we exist in a reality that is temporal and causally structured. We may not be able to point to it in experience. This in some ways is the limit of Hume’s “skepticism”. But, that we can move forward without these categories is impossible. And this is what if often overlooked in Hume. Hume spends most of his time proving what is not in experience. He spends little on what is presupposed by experience. Hume calls it custom.
What I will say is that Hume means to not wax metaphorical. He was interested in only saying what was sayable. And, what is sayable is that time-invariant causal structures are not found in experience. What is also sayable is that I cannot understand action except in time, and as an effort to take advantage of time-invariant causal structure of reality.
It is the negative route that necessitates. Try presupposing no causes and no effects, just randomness, chaos, and variability undetermined. Well, I couldn’t even have typed that sentence given that each active stroke of the finger on the keys presupposed the effect that would be the result of the cause in time.
Onward to one look at time with a dose of psychology.