According to the passage view, these are more than just perceptions - they are features of the real world revealed to us through the 'private door' of consciousness (see Eddington citation below). But are they? Our approach here is to begin by asking some questions about why we think time has these features, then to relate these to the workings of mind - memory in particular. This provides a bridge to the physical world, since the recording of memories is an increasingly well understood physical process.

Having connected our perceptions of time to the physical world it then becomes appropriate to ask: Why are the psychological and thermodynamic arrows aligned? Eddington hypothesized that the brain keeps track of time using 'entropy clocks', though there is little evidence for this. Alternative approaches take us into the realm of information theory. Some authors appear to simply presume that the arrows must align, while others have attempted to prove that memories can only be formed in the direction of increasing entropy. This part of the map includes two attempted formal demonstrations, one appealing to an analogy between human and computer memories and a different approach that draws on quantum theory.

Do they stack up? It would seem not - powerful objections have been mounted against both. So where does that leave us? These questions are addressed in this part of the map.

In addition to the passage view components, two additional aspects of how we perceive time - two additional asymmetries - are considered:

1. The asymmetry of agency - the fact we think we can influence the future through our actions, but not the past.
2. The asymmetry of concern - we worry about a visit to the dentist tomorrow more than one that took place yesterday.