agent to approach affordances and evade disturbances. But a landscape may also
exhibit more abstract features that make it attractive.
Prospect
Perhaps the most basic abstract feature characterizing attractive landscapes is prospect
[Appleton, 1996; Hudson, 1992]. A landscape has prospect if it offers a far and wide,
panoramic view. Prospect is normally high from the top of a mountain or in an open
plain, and low at the bottom of a pit or in a dense, dark jungle. The more and the
farther you can see, the better you can distinguish the different dangers and
opportunities in your environment, and therefore the easier it becomes to plan your
further course. This makes landscapes with prospect intrinsically more attractive.
In a wider, more abstract sense, prospect refers to the number of things an
agent can foresee (prospect derives from the Latin verb prospicere, which means
‘look forward’). Prospect in this sense is opposite to blindness, ignorance or
uncertainty, which indicate a lack of foresight. However, prospect is not the same as
certainty about what will come: prospect rather indicates potential, i.e. the remote
availability or presence of affordances to be exploited or disturbances to be avoided.
Whether the affordance is effectively exploited depends on the agent’s choice of
course of action, and on eventual diversions interfering with that course. The larger
the prospect, the easier it is for the agent to set out, and navigate along, a high-fitness
course without risk of diversion, and hence the more the agent is in control of its near-
term future. Therefore, it is clear that agents will be motivated to maximize their
prospect.
Several authors [e.g. Neisser, 1976; Riegler, 2001; Hawkins & Blakeslee,
2005] have argued that prediction constitutes the essence of cognition: the function of
knowledge and intelligence is to enable an agent to anticipate what it will encounter,
so that it can prepare for future events by action, reflection, or simply being
particularly attentive or sensitive to the most likely outcomes (priming). Obviously,
the better an agent can anticipate the diversions it will encounter, the more efficient it
will be in exploiting the affordances while evading the disturbances: it is much easier
to avoid a danger if you can see it coming well in time. Prospect may be conceived as
the extent of this anticipation, i.e. as the number or proportion of impending
diversions that can be foreseen—perhaps weighted by the degree of certainty of those
predictions. As depicted in Fig. 3, prospect can be visualized as the area ahead that is
perceived by the agent, either directly through its eyes (as in the case of a landscape),
or more indirectly through its “mind’s eye”, i.e. its powers of conceptualization,
inference and prediction (as in the case of a more abstract space of possibilities).
We started from the principle that uncertainty cannot be eliminated. Therefore,
prospect must remain limited. This is obvious in real landscapes: normally there are
always obstacles to vision, such as hills, bushes, walls or the haze of distance. Even in
a flat plain with perfect visibility you cannot see further than the horizon. Yet, with a
little bit of effort obstacles can be circumvented, and sustained advance will make the
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