In this pleasingly short book, Ronald Giere continues his explorations of naturalistic approaches to understanding science.  The key idea in this volume is ‘perspectivism’ and his aim is “to develop an understanding of scientific claims that mediates between the strong objectivism of most scientists, or the hard realism of many philosophers of science, and the constructivism found largely among historians and sociologists of science” (p. 3). 

After setting out the opposed positions between which he intends to mediate, Giere’s strategy is to use color vision as an exemplar of the sort of perspectivism he believes characterizes science.  Chapter Two sketches what contemporary science of color vision has revealed; Chapter Three extends these insights to scientific observation in general.

In Chapter Four Giere argues that “conception is a lot like perception, or, that theorizing is a lot like observing” (p. 61) so the various aspects of perspectivism that he has uncovered in vision and other observation can be found also in our theories.  This chapter is the heart of the book since it tries to establish the truth and distinctiveness of Giere’s perspectival approach to scientific knowledge.  The book concludes with a chapter on “distributed cognition”.

Giere is much closer to first-order science and inquiry than most other philosophers — he makes the point that much of what passes for philosophy of color vision is woefully out of touch with what we have actually discovered.  So it is worth taking a closer look at  his discussions.  In the preliminary scene-setting he notes that a naturalistic approach to normative issues of which methodology is to be preferred will insist that it is not an a priori matter but a purely instrumental, empirical question of what works.  There are many such brief remarks made in passing throughout the book from which one can learn.

But the main worth of this book lies in its perspectivism.  What exactly does this convey?  Giere is clear that it does not degenerate into a crude relativism.  One of his early suggestions (p. 13) is to appeal to perspectives in viewing a scene.  The front view of a building is usually very different from the back or side view.  Each one is legitimate, each reveals a truth, though of course not the whole truth.  His main example is color.  “Colors are real enough, but … their reality is perspectival …. a genuine alternative to both objectivist realism and social constructivism” (p. 14)  He immediately distinguishes two “dimensions to the perspectival nature of claims about the output” (p. 14) both of perception and of the instruments used to observe:

l        the systems are responsive only to a particular kind of input;

l        no system is totally “transparent”, they all make a contribution to the outcome. As a consequence, we cannot transcend our human perspective.

When applied to theories, the idea is that a theory is a matter of fundamental principles (natural selection, the Schrödinger equations, Newton's laws, etc.).  These are not true generalisations about the universe, but constraints on the construction of models of aspects of the world.  Questions of truth, or  rather closeness of fit, arise when we ask how well such models capture the goings-on to be explained, but those goings-on are not raw data but themselves models of data, statistically processed and cleaned up.

Giere's review of color science stresses the variety of actual color processing systems and the contingencies of such matters as the opponent system for hues — this means, he says, that the notorious red-green incompatibility is neither “a synthetic a priori truth, nor a truth of grammar, as Wittgenstein might have said …, but a straightforward scientific conclusion” (footnote 4 on p. 121). His survey issues in an interactionist picture: “colors are the product of an interaction between aspects of the environment and the evolved human [or other animal] visual system” (pp. 31-32), or again colors are to be taken as “neither completely objective nor purely subjective, neither as properties of either parts of the material world or of subjective experience, but as a property of an interaction between the material world and human observers” (pp. 38-39).  Plausibly he suggests that color scientists tend not to distinguish this view that they actually hold from a crude subjectivism, since both make colors crucially dependent upon the existence of variously structured perceivers.

Some consequences of his position are sketched.  Suppose a carpet is seen by a dichromat and a trichromat.  There is no objective difference; only color as seen by a dichromat and as seen by a trichromat.  More information is derived by the trichromat.  And different perspectives are always compatible (cf. p. 33).

Expanding on what is characteristic of perspectives, Giere argues that they are all partial: we respond to a portion of the electromagnetic spectrum, and are blind to the rest.  He cautions against mistaken construals of this fact: we and other perceivers do not live in different worlds, but one world (though he wants us to take this as a methodological injunction, not a putative metaphysical truth); we do not experience colored representations but the world itself.

Giere continues by considering the role of instruments in our scientific observation of the world.  He admits that an overarching aim has been to reduce the subjectivity of ordinary perception, but insists that such observation remains perspectival in several respects: our instruments respond only to part of the reality around them, they are limited and have finite powers of discrimination even in that response.  Giere's examples are taken from astronomy and neuroscience.  He describes the complex processes that create “true color” photos of the Triffid nebula, but these pale before those involved in many other astronomical pictures: for one Hubble photo, detectors sensitive in the infra-red, 13 hours of exposure, four different filters, gravitational lensing, …. Giere's conclusion is that we do not discover the intensity and distribution of gamma rays at the centre of the galaxy, say, but rather those aspects as indicated by a particular instrument.  Different instruments give different 'takes' on the same portion of reality.  Giere considers whether this argues for there being something objectively there; his answer is that it indicates that something is there, but “to be an object detected in several different perspectives is not to be detected in no perspective whatsoever” (p. 58); we should not think of telescopic discoveries as moving us from a limited human perspective to a non-perspectival objective truth.

As noted already, Giere wants to carry over his perspectival account of perception and observation to the ways scientists represent some aspect of the world for their various purposes.  While scientists use various things to do this representing — diagrams, graphs, computer images, etc. — Giere focuses on theories, and offers the account sketched earlier.  In discussing the ideas that a representational model fits some aspect of reality, Giere argues that the partiality that characterizes perspectives entails that what is revealed from a particular perspective must be incomplete in some way: those aspects omitted have causal connections to what is included, so some interactions for the latter are omitted and so the model cannot fit exactly (p. 66).

There are interesting discussions of maps and modelling in the theory chapter that I shall pass over in silence to allow myself one doubt about his enterprise.  Giere opposes absolute objectivity in favour of his perspectival variety.  Taking uncontentious examples like 'A is to the left of B' we can agree that this is elliptical (a notion I have explored elsewhere) for 'A is to the left of B from perspective P'.  But we can also say that in these cases the non-perspectival claim is literally incomplete, incapable of truth or falsehood.  The only truths, which you can call absolute if you wish, are the fuller versions it is usually too pedantic to utter.  But what Giere seems to need in his discussion of color is the additional idea that the crucial element in the relation or interaction only exists in that interaction.  Although we may think of it as an intrinsic property of things, it isn't.  His denial of absolute objectivity for claims about gamma rays in the centre of our galaxy cannot be the dubious idea that we cannot justifiably drop the perspective in such claims ('A is B according to COMPTEL' is meaningful but so is the simpler 'A is B', which might be offered by way of explanation of the former; it is not elliptical like 'to the left of').  But it doesn't sound much like what I called the additional idea in the case of colors either — that the gamma ray flux only exists because of the interaction between the galaxy and our instruments.  So while there is much to be gleaned from Giere's accounts of observation and theory, I am inclined to doubt that Giere has found a middle way between what he regards as an excessive objectivism and the relativism he rightly wishes to reject. More generally one might go on to wonder whether Giere's detailed account of scientists comparing models of the world generated within the constraints provided by a set of principles with models of data need actually supersede the traditional picture of them trying to uncover the actual ways of working of the universe.  The best we can do is compare à la Giere, but the intent and what we postulate by way of explanatory story is to grasp the objective truth, not merely to claim that this bit of reality can be adequately modeled in this story.

Giere points to a serious problem with this traditional way of construing scientific theorizing: there are unlimited numbers of alternative theories that would do as good a job with respect to our actual data (p. 91).  Simple realism has the problem of explaining why we can ignore them, while Giere simply avoids the problem by insisting on the restriction to the perspectives currently in play.  My feeling that this is too facile does not detract from my appreciation for the many insights contained in Giere's work.  It deserves further development and critique, and for the non-professional it gives a good feeling for the realities of scientific work that are often obscured by more traditional philosophizing.

© 2007 Ed Brandon

Ed Brandon is, by training, a philosopher, and now is working in a policy position in the University of the West Indies at its Cave Hill Campus in Barbados.

Categories: Philosophical