The nature of time remains a profound mystery in physics and philosophy. Does time fundamentally exist as part of the deep structure of reality? Or is time more akin to a human construct – a useful mathematical abstraction but not objectively real? In this dialogue, perspectives on both sides of this debate are explored, including how physics incorporates time in its equations, the philosophical implications of relativity, and the tension between mathematical and perceptual views of time. Key arguments are presented for and against time as intrinsically real versus time as an emergent phenomenon or illusion arising from human cognition. While a firm conclusion is elusive, the discussion highlights the nuances in viewing time as either fundamental or constructed and aims to spur further reflection on this complex topic. On one hand, our perception of time does seem to pose a challenge to viewing time as just a mathematical construct. The fact that we experience events unfolding sequentially and have memories of the past, is hard to explain if time is not fundamental. How could evolution produce such a coherent sense of time passing if it does not objectively exist? This lived experience lends credibility to time being inherent to reality in some way. However, we also know human perception is fallible and our everyday intuition can be misleading when it comes to fundamental physics. For example, we perceive motion very differently from how physics describes it in relativity theory. So we can’t always trust our subjective experience as a guide to what is fundamentally real. Our evolved cognition may impose an illusion of time even if it’s not objectively there in the external world. On the other hand, even as a construct, time appears universally experienced by all humans. This intersubjective quality makes it seem more than just an individual illusion. If time was just created by human minds, wouldn’t there be more variability in how it is perceived? The fact that we all experience time passing in a shared way points to time having some external physical basis, even if indirectly. But then again, some modern physics theories like eternal inflation or quantum many worlds imply reality branches in every possible way. So in some sense all possible perceptions of time may exist somewhere in the superposition of global wavefunction. The universal experience of time passing may just be a quirk of the subset of universes we inhabit rather than applying to all existence. This back and forth highlights why it’s so tricky to firmly conclude whether time is fundamental or constructed. Both perspectives can marshal reasons in their favor. Perhaps a synthesis of both views is needed – time may be real in some sense while also having a constructed element. But the philosophical debate continues! What do you make of these arguments? Do you find one side more compelling on balance?