But is that so?
Should we really believe in the scientific realism
as the best explanation of the success of science?
Not so fast, the anti-realist would reply.
Now, scientific anti-realism is a house with many mansions and
a prominent variety in modern philosophy of science,
is the variety known as Constructive empiricism, which has been elaborated
by the American philosopher Bas van Fraassen since the early 1980s.
A distinctive aspect of Constructive empiricism
is that agrees with scientific realism about the semantic aspect.
Namely a constructive empiricists would agree with the scientific realists
that we should take the language of science at face value.
That we should understand that the main thread of terms such as planet,
or electrons or whatever as we're faring to objects in the external world.
But the constructive empiricists would disagree
with the realist about the spending prospect.
In other words, the constructive empiricist would claim
that we don't need to believe theories to be true in order for them to be good.
Now the name constructive empiricism stresses that there's an important element
of construction that goes on in scientific activity, especially in the way we
build scientific models, which are meant to be adequate to the phenomenon.
And that the word empiricism emphasizes that this is ultimately an empiricist
position, in believing that our knowledge should be confined to the available
experimental evidence, as opposed to going beyond
the available evidence and claiming to discover truth about the unobservable.
So what is the unobservable?
And what does it mean that we construct models that are adequate to the phenomena,
but they don't necessarily tell us the truth about the unobservables?
Consider minerals,
there are some observable phenomena that we can study about minerals.
For example, their melting points, their hardness,
how easily they may combine with each other but there are other aspects,
which are strictly speaking, unobservable to the human eye.
For example, chemistry classifies gold as the metal with atomic number 79,
and the atomic number is defined in terms of the number of protons and
electrons distinct to the element.
So strictly speaking,
whereas we can observe with our naked eye the property of melting point,
hardness and so forth, we can't observe with our naked eye the atomic number or
the molecular composition of minerals but we do construct models of them.
Indeed, we do construct informative models like this crystal models of minerals, for
example which nicely represents the molecular composition
using both the different colors that arrange according to some dramatic
structure that is meant to be adequate the phenomena.
For example, it's meant to represent how easily we can slice the minerals along
some of these chemical bonds.
Yet the constructive empiricist would insist we shouldn't take more those as
providing the truth about the unobservable, namely about atoms,
molecules, or chemical arrangements.
Models must only be adequately observable phenomena.
They are useful tools to get calculations done but
they don't deliver any truth about the unobservable entities.
So constructive empiricism would insist that scientific theories
not to be true in order to be good, they only need to be empirically adequate.
And a theory is empirically adequate if whatever the theory says about observable
things and events in the world past, present, and future, is true.
In other words, the theory is empirically adequate if the theory saves
the phenomena.
In this way, Empirical adequacy rather than truth becomes the aim of science.
Now, this conclusion chimes in many ways with the old view of
ancient Greek astronomy, that the aim of a science was to save the phenomena, but
there aer some important differences.
For ancient Greek astronomy the aim was to save the phenomena because Ptolemy and
and so forth, so that human knowledge cannot bind with divine knowledge.
But after Galileo, that view could no longer be maintained.
So for modern science and the reason why some anti-realists may want to
insist that the aim is not truth but empirical adequacy, has nothing to do with
distinction between human knowledge and divine knowledge, and all to do with
the metaphysical commitment that theorists bring along with them on one hand.
And on the other hand, with the idealized,
an abstract nature, of the synthetic models that we build.
As far as the latter is concerned, in the past 30 years or so,
an increasing literature in philosophy of science has stressed how abstraction and
idealization entered into the construction of models.
So that although the models are very useful and explanatory tools in every day
practice, they may not necessarily be the true of states of affairs in the world,
if not in a very idealized sense or in very idealized circumstances.
For example, in this double helix stick and
ball model of the DNA sequence, we need to abstract from the terribly complicated
cellular environment in which DNA sequences can be found in nature.
And we also need to idealize the atoms involved
as perfectly of balls of different colors,
as well as we need to idealize the direction of the helix spiral,
right-handed or left-handed, to represent the different forms of the DNA molecules.
So models can be very useful and
informative and exploratory even if we don't have to
think of them as providing a perfectly true picture of the target system.
As far as metaphysical commitment is concerned,
the constructive empiricists that would insists that she could do
exactly the same good quality science as the scientific realist.
In other words, while doesn't need to believe that theory's true to explain why
we have such a successful science, one can just say that just say that the success of
our present theories is the result of a struggle for
survival across centuries, so the best theories in mature
science are the ones that have proved survival adaptive.
Are the ones that have proved to save the available evidence
without necessarily being true.
So in reply to the argument, the constructive empiricists would insist that
we can give an explanation, some sort of Darwinian explanation, of why scientists
are successful by appealing to empirical adequacy rather than truth.
Moreover deconstructing empiricists would insist that scientific realism is some
sort of high-risk strategy when it comes to metaphysical committment.
What if the unobservable entities that we take to be true in the present signs turn
out to be like unobservable entities that people in the past believed to be true,
and they proved to be nonexistent.
What if, in 100 years time, our electrons and neutrinos and
protons and DNA turn out to be like the either or the or the caloric or
all those other unobservable entities that people in the past have believed and
that are now just the remnant of a discarded past.