because they are rare (they could become common) but because they
were not part of the conditions prevailing when the relevant genes
were selected. Whatever genes control the modern human tooth-
development appeared in an environment where people chewed their
food, where that food consisted of plants and animals, where lollipops,
candy bars and intravenous drips were absent.
In much the same way, most normal children have a stepwise lin-
guistic development that invariably includes a huge vocabulary expan-
sion between the ages of two and five, a one-word-sentence stage fol-
lowed by two-word utterances followed by the full syntax and
[114] morphology of their language. But this again requires a normal envi-
ronment, which includes people who speak such a language and speak
it in interacting with children. Children raised in isolation may not
develop full linguistic capacities. To sum up, a normal environment is
indispensable to development if you have the right genetic equipment
that prepares you to use resources from that environment, to build
your teeth out of normal nutrients and to build your syntax out of nor-
mal linguistic interaction with competent speakers.
Which leads us to another, much more important question. As I
said, particular ontological categories and inference systems are found
in all normal human minds, from an early age. I should have empha-
sized the term human. For the particular architecture I just described
is indeed characteristic of humans. We intuitively make distinctions
such as those between inanimate stuff as opposed to goal-oriented
stuff, or between naturally occurring objects (mountains) and created
ones (bows and arrows), between human agents and nonhuman ani-
mals. But there is no metaphysical necessity to do it that way. Indeed,
many philosophers and scientists think that some of the distinctions
we intuitively make (e.g., between humans and animals) are not that
justified. Our intuitive ontology is not the only one possible.
To see this, consider this simple scene. Marywith her little lambare
resting under a tree next to a lamppost. Now imagine how this is
processed in the minds of different organisms. For a human being,
there are four very different categories here (human, animal, plant,
artifact). Each of these objects will activate a particular set of inference
systems. The human observer will automatically encode Mary's face as
a distinct one but probably not the sheep's, and will consider the lamp-
post's function but not the tree's. If a giraffe were to see the same
scene, it would probably encode these differently. For a giraffe there is
probably no deep difference between the sheep and Mary (assuming
RELIGION EXPLAINED