…on the one hand, scientific explanation requires us to say that conscious beings emerge only after a long causal sequence unfolding in time. On the other hand, time itself — understood as succession or temporal sequence — exists only as a form of representation, and therefore presupposes a knowing subject. Schopenhauer insists that both are undeniable facts, and that neither can be eliminated without incoherence.
It is in this context that he writes that the world comes into existence only with the “first eye that opens" (ref). The emergence of the first perceiving being does not occur in time in the ordinary sense, because time itself becomes meaningful only with the possibility of perception. And yet, once time appears, it necessarily presents itself as having an infinite past stretching behind that first present moment. The entire temporal history that science reconstructs is therefore simultaneously dependent upon, and explanatory of, the emergence of consciousness.
Schopenhauer does not treat this as a defect of reasoning, but as an antinomy³ inherent in our faculty of knowledge. “Time has no beginning”, he writes, “yet all beginnings are in time”. The world, considered as appearance, cannot exist without a knowing subject; yet the knowing subject, considered as phenomenon, appears only within the world. The contradiction dissolves only when time is recognised, with Kant, as belonging to the form of representation rather than to things as they are in themselves. Likewise, minds only appear in sentient beings such as ourselves and the higher animals within the world, but the world itself — as a meaningful, temporally ordered whole — is something that is only intelligible in relation to a mind, and can’t really be understood as if from a standpoint somewhere outside of it ~“About Time”, excerpt.