I am probably not alone here since the objective-subjective or fact-value dichotomy is strongly embedded in our culture.
Here is an outline of a study programme I am currently undertaking based on his readings.
Putnam's work represents a critique on various levels of the entrenched ("ideological") dichotomy between the "objective" (truth) and "subjective" (values).
The big R - Realism approach is that we can make scientific statements that accurately represent a mind independent reality. For example, Newton's Laws enable us to accurately send a rocket to the moon. However, the subsequent development of science reveals reality to be far more complex. Einstein's theories are conceptually quite different and Newton's maths turns out to apply only under limiting conditions.
The opposite approach to big R Realism is that all schemes of thought or points of view are hopelessly subjective. Cultural relativism holds that what we think depends on our culture, which is continually in flux.
Putnam has played a leading role in developing a third way which rejects both of the above extremes. It may be called internal realism or pragmatic realism. To describe it with a Hegelian metaphor: the mind and the world jointly make up the mind and the world.
The mind does not simply copy the world described by One True Theory. There is no Gods Eye View. It is time to recognise that the project of trying to define the furniture of the world (ontology) has failed.
Putnam has developed a similar treatment of epistemology or knowledge claims. It would be a mistake to demarcate "objective" science from "subjective" ethics. Neither scientific nor moral truth is either objective nor subjective (culturally relative). Rather, there are better or worse versions.
Scientific reductionism, although useful in some respects, comes up against limits which cannot be overcome.
Some of the key reasons for this world view are as follows:
Even at a simple level different ways of describing the world are equivalent but non compatible. What exists depends on which conventions we adopt. One simple example provided is mereological sums (details not provided here). The world does not dictate a unique "true" way of dividing the world into objects, situations, properties etc.
The nature of science:
Science is a diverse enterprise and just one good way to reason about the world. It is not a master philosophy.
A cut and dried description of the world - physics envy - has not eventuated, including in physics. The cut between the observer and experiment in Quantum physics means that a Gods Eye View is not possible.
Scientific epistemic values such as coherence, plausibility, reasonableness and simplicity are values too, just as are ethical values such as courage, kindness, honesty and goodness.
Science encompasses a broader notion of rationality than any formal scientific method which resembles an algorithm.
For example, we accept Darwin's theories because they provide a plausible explanation of the evolution of life. Not because they conform to any clearly defined scientific method.
Real scientists rely on their intuition and imagination extensively in developing their innovative theories. In their theory formation scientists postulate unobservable causes for observable events. If humans had a firm prejudice against the speculative and unobservable then we would not be good scientists.
Putnam has completed cases studies of the work of particular philosophers of science such as Thomas Kuhn and Karl Popper.
Emergent properties of thought (mental states) such as loving, hating, desiring, believing, judging, perceiving, hoping can't be reduced to the physical. We are stuck with this dualism. (Brentano's problem).
"I am, then, a dualist, or, better, a pluralist. Truth, reference, justification - these are emergent, non-reducible properties of terms and statements in certain contexts. I do not mean they are not supervenient on the physical; of course they are. My dualism is one not of minds and bodies, but of physical properties and intentional properties. It does not even yield an interesting metaphysics."The vanishing a priori:
(Three Kinds of Scientific Realism, In Word and Life, 493)
All the candidates for fundamental or foundational knowledge have progressively disappeared over time. eg. Euclidean geometry changed from the one true way to just one way amongst other ways of perceiving spatial relations.
update July 8th, 2013: Since there are no firm foundations in epistemology then we are stuck with better (more fruitful, coherent) or worse representations of reality as the best we can do, not true or false version in an absolute or "true scientific" sense. See "Pragmatic principles" below.
Breakdown of the fact / value or objective / subjective dichotomy:
The idea that value judgements are "subjective" and that statements of fact are "objective" is often regarded as common sense in our current culture. The purpose of Putnam's various arguments are to challenge that "common sense"
Human flourishing (the purpose of philosophy):
Scientism as a monistic world view represents an emotional craving for clear answers. Rather than a one sided reliance on problem solving, philosophy should help us acquire better metaphors and habits for looking at the world such as adjudication and reading and interpreting good literature. Facts and values become a distinction rather than a dichotomy.
Literature and philosophy "may be rich or impoverished, sophisticated or naive, broad or one sided, inspired or pedestrian, reasonable or perverse and if perverse, brilliantly perverse or merely perverse" (from Realism with a Human Face, p. 183)
Pragmatic principles from the heritage of Peirce, James and Dewey:
(i) antiskepticism: doubt requires justification just as much as belief
(ii) fallibilism: there is never a metaphysical guarantee to be had that such and such a belief will never need revision
(iii) there is no fundamental dichotomy b/w “facts” and “values”
(iv) practice is primary in philosophy
MAJOR WORKS OF HILARY PUTNAM:
Mathematics, Matter and Method. Philosophical Papers, Vol. 1 (1975)
Mind, Language and Reality. Philosophical Papers, Vol. 2 (1975)
Meaning and the Moral Sciences (1978)
Reason, Truth and History (1981)
Realism and Reason. Philosophical Papers, Vol. 3 (1983)
The Many Faces of Realism (1987)
Representation and Reality (1988)
Realism with a Human Face (1990)
Renewing Philosophy (1992)
Words and Life (1994)
Pragmatism: An Open Question (1995)
The Collapse of the Fact/Value Dichotomy and other essays (2002)
Ethics without Ontology (2004)
Many of Putnam's books can be downloaded from here.