To paron is the substantivised participle of πάρειμι ("to be present, to be at hand"), literally "what is present," "what is at hand." In Stoic metaphysics of time, and in Marcus's ethics, it is the only moment of time that possesses real existence. The past (παρῳχηκός, τὸ παρεληλυθός) no longer exists; the future (τὸ μέλλον) does not yet exist; the only thing real, properly speaking, is τὸ παρόν.

This position inherits Aristotle's analysis of time (Phys. IV 10–14): the "now" (νῦν) is a boundary without duration between past and future. The Stoics preserve the ontological difference past/present/future and develop it ethically: the only thing I own is τὸ παρόν. Everything else is either already taken from me or has not yet been appropriated.

Aristot. Phys. IV 10–14, 217b29–224a17 (the classical statement of the question of time and the "now"); SVF II 509, 510 (the Stoic doctrine of time and of the unreality of past and future); Plut. De comm. not. 1081f–1082a (the polemic against the Stoic understanding of time); LS 51. To paron is a frequent term in Marcus: Med. 2.14 (two arguments); 3.10 ("only the present can be lost"); 4.26; 06-02 (τὸ παρὸν εὖ θέσθαι — to dispose the present well, even in dying); 06-32 (the mind deals only with the present activity); 07-08 (you will meet the future with the same reason you now use πρὸς τὰ παρόντα); 07-27 (of τὰ παρόντα pick the choicest — without overprizing them); 07-68 (τὸ παρὸν is always the ὕλη of virtue: "you are the thing I was seeking"); 08-36 ("do not burden the present with the imagination of the whole past and future"); 12.1 ("everything you await by roundabout means, you can have now"); 12.3; 12.26 ("remember that only the present belongs to you").

In 02-14 τὸ παρόν receives its most condensed and elegant formulation in two arguments:

1. The argument from the levelling of losses. A long life and a short life lose the same thing — because both lose only τὸ παρόν, the only moment they actually have. "The longest life is no different from the shortest" (εἰς ταὐτὸν καθίσταται τὸ μήκιστον τῷ βραχυτάτῳ).
2. The argument from ownership. The past and the future cannot be "taken away," because no one owns them: "for what a person does not have — how could anyone take it away from him?" (ὃ γὰρ οὐκ ἔχει, πῶς ἄν τις τοῦτο αὐτοῦ ἀφέλοιτο?). One can own only the present.

The ethical turn: this analysis redefines the fear of death. Death is ordinarily feared as "the thing that takes away my whole life." In Marcus, death takes away only the present — a moment the length of a blink. The length of the lived past does not enter the reckoning of losses, because the past is no longer mine. With this, EXERCISEthe memory of death in Marcus takes on a very specific turn: death is easy not because it does not exist, but because it takes away the minimum — the one moment that is at hand, which is in any case continually departing.

Connection with practice: EXERCISEattention and refusal of postponement both rest on τὸ παρόν, but from different angles. The παρόν of EXERCISEprosokhe is where the attention is to be (not in past offences, not in future plans); the παρόν of no-more-delay is when to act (now, not "later"); the παρόν of 02-14 is the metaphysical support of the first two: the present is not merely a "convenient focus" but the sole thing that is at hand.

In 03-10 the present is called τὸ ἀκαριαῖον — "the instantaneous, the uncuttable" (the indivisible point of the "now") — and is joined to the view from above: each lives only this instant, and small is not only the life lived but the corner of the earth and the longest after-fame. Thus the discipline of the present meets the relativization of space and fame: the single "now" is set against all the small things toward which vanity reaches.