For an autopoeitic living system like a human being, real economic action, the health of body and mind as the advancement of consciousness are the possible gateways to connect to the universal principles of cosmic law.
The ancient Greek word for 'truth' was ἀλήθεια (alētheia). In vernacular use, it meant truth as opposed to a lie, reality as opposed to mere appearance.
In generally Peircean semiotics, it's plausible to understand iconic semiosis in particular as the causal connection between sentient humans and material or extant reality, where all five human senses are distinct modes of iconic semiosis. The causal structure of our human neurology is directly connected to the causal structure of physical reality.
This implies that iconic sentience is grounded in indexical causality. Indeed, this is so: the causal laws of the cosmos establish and constrain the universal and probabilistic presence, properties, and relations (including connectedness) of everything in existence (including humans), past, present, and future. Cognitive human perceptual experience of the cosmos we inhabit and of ourselves and one another is essentially and primarily causal (indexical). The sentient signs (icons) forming that experience are the effects of those external and internal causal constraints. From the thing perceived to perception of that thing the semiosis (sign-processing) is pervasively causal.
Causality is the universal medium of connection between cognition and the cosmos.
"Kosmos" is the Greek word for order (and beauty, because order means beauty to Greeks). Contributing to order in this world means contributing to Kosmos in this sense, making yourself part of the Kosmos, co-operating with the ordering god (in Plato's sense). -- If the world is a physical world ... is an open question. You only have your perception of it. Blending in with your reason and understanding into this perceived world is all you can reach. It should be enough.