90 J.J. Haldane
The Emergence of Life and the Origins of ReproductionOld-style vitalism, the dualistic idea that living things are composites of
two substances, a quantity of inanimate matter and a motivating élan vital or
life force, has little to be said for it. Indeed, from the point of view of the
Aristotelian picture I favour it is quite the wrong way to think of the nature
of living things. On this preferred account the difference between an inani-
mate object and a living thing is not that the latter is a lump of matter plus an
immaterial agent resident within it; rather it is that the latter has an intrinsic
functional organization in virtue of which its movements are explicable in
terms of ends towards which they are directed. Notice that this is an avowedly
non-reductive and teleological characterization. That is not a problem for
me; rather it presents a challenge to the anti-teleologist to provide a non-
teleological account of the difference between living and non-living things.
Appeal to their matter alone will hardly do. First, the pure reductionist
will not want to rest his account at any level that is not further reducible
to physics, so an ineliminable chemical theory will be problematic. Second,
bracketing this point, no merely compositional account seems adequate, since
it need not be an issue of contention what non-living and living things are
made of. The question is what makes one and not another alive. To deploy
the Aristotelian terminology it may be agreed that inanimate A and animate
B have the same kind of material cause (physical substratum); the issue is
whether this is sufficient to explain their natures as kinds of things, living
and non-living respectively. According to the neo-vitalist account each has
a formal cause, that which makes it be the sort of thing it is, and the latter
has a final cause – its organic well-being or efficient functioning – towards
which it is moving.
I began this contrast in terms that suggest comparing two objects sitting
side by side on a table – or more realistically two specimens beneath a micro-
scope or in some other apparatus. But any purported naturalistic account of
the nature of vitality will want to serve in a historical account of the origins
of life. That is because the naturalism in question is materialist and involves
the familiar idea that life itself has evolved from non-living matter. Thus the
difference between the living and the inanimate has first to be specified, and
then it has to be shown how there could be a natural transition from one kind
of state to another. There will be no principled obstacle to success in the
latter task if the former leaves no vitalist or teleological residue. For then one
will only have to show how one spatio-temporal arrangement of microphysical
particles led to another. But notice that this course involves the denial that
there are any such entities as living things and that there was ever any such
process as the emergence of life. In reality, the situation is no different from
that obtaining before the earth and the sun were formed.