Time past and time future
Allow but a little consciousness.
To be conscious is not to be in time
But only in time can the moment in the rose-garden,
The moment in the arbour where the rain beat,
The moment in the draughty church at smokefall
Be remembered; involved with past and future.
Only through time time is conquered.
- Burnt Norton, Four Quartets, T.S. Eliot, published in 1909–1935
There are predominantly two major views on the ontology of time, as phrased by McTaggart (1908) as ‘A-series’ of time and ‘B-series’ of time, although I prefer the more direct and precise way of identifying the two theories—the dynamic theory and the static theory. The general camp of dynamic theory includes Growing-Block Theory (GBT), Moving-Spotlight Theory(MST), and presentism. What is common among those views is the fundamental belief that time passes and that time has a dynamic nature. On the other hand, static theorists, who mostly endorse the Block-Universe Theory (BUT), deny the existence of any apparent dynamic quality of change nor any special nature of the present. Hence, the passage of time is thought to be illusionary to their beliefs.
It is essential to divide the question of the passage of time into the question of subjective passage and objective passage. The following two questions arise when we attempt to distinguish between subjective passage, as experienced phenomenologically, and objective passage, which concerns the fundamental ontology of time itself:
The phenomenological question: Why does time seem to us as if it passes?
The ontological question: Is the nature of time dynamic?
Full essay available here