Reply to Smart 179of self-replication is novel and not explicable by reference to lower-level
entities and properties.
Standard evolutionary explanations posit replication as spontaneously aris-
ing some three or four billion years ago in a form more primitive than DNA.
Needless to say there is no direct evidence of this, rather it is an assumption
of naturalistic theory. The behaviour of DNA itself is acknowledged to be so
qualitatively advanced that it is unimaginable that it could just have sprung
into being uncreated. So the task is to show how DNA could have arisen
from more primitive replication, say RNA, and how that could have resulted
from non-replicating systems. Although molecules exhibit dynamic properties
they are not normally self-duplicating, so the question remains: how could
replication and hereditary variation arise?
Talk of ‘proto-replicators’ is vulnerable to a version of the dilemma with
which I challenged the claim that intentionality arose from protorepresentation.
Representing or replicating very many features is certainly different from
representing or replicating very few, but (paceSmart’s remarks in his reply,
chapter 3, p. 156) it is a difference of the wrong kind so far as the needed
explanation is concerned. Low level is not no level, and it is the jump from
none to some that needs to be effected. I conclude, a priori, that this gap is
one of kind not quantity. The emergence of reproductive beings is radical and
thus by definition not naturalistically explicable. If natural explanations were
the only sort available we might despair of understanding. But there is another
way of accounting for the emergence of novel entities as when a painter
brings together quantities of powder suspended in oil and fashions a likeness
of a sitter. Such is the style of explanation I offer of the emergence of life.
Like the portrait it is the work of creative intelligence.
I have already touched upon the question of how mindedness introduces a
domain distinct from that of physical properties and relations. The character
of this difference has an important part to play in the extended argument
(schematized in figure 4.1B) from thought and language to the existence of
God as source of conceptual activity. Smart’s rejoinder is principally addressed
to the premiss concerning intentionality. Since I remain attached to what
I argued earlier, I suggest that readers compare what each of us has had to say
on the matter and draw their own conclusions. I would only add by way of
encouragement that the issue of intentionality is of immense interest and
importance in its own right.
3 Metaphysical Matters
Thus far, the left-hand side of figure 4.1A has not been mentioned. The
cosmological reasoning set out in section 6 of chapter 2 is really a presentation