The first essay establishes that the fact/value distinction (a later incarnation of Hume's "you cannot derive an "is" from an "ought" thesis) rests on a dubious positivist definition of "fact" that derives from sense impression. In the second, Putnam explains that the values that science assumes aren't necessarily moral or ethical ones, but epistemic ones. Epistemic values like "coherence" and "simplicity" are assumed in the scientific pursuit, yet science continues to be thought of as wholly objective. John Mackie argued that words like "cruel" and "just" were simply words that described "natural facts," instead of realizing that they cannot be used intelligibly without employing some kind of evaluative judgment.
The third essay transposes this debate into the world of classical economic theory. This same debate found itself transposed into the field of economics ensconced within the framework of a Benthamist moral calculus, but were removed by the empiricist is/ought distinction (later, the work of the positivists.) Amartya Sen's project is to reintroduce ethical concepts and norms (once so lauded by Adam Smith, but since having been forgotten) back into the discourse on classical economics without losing any of its original rigor. Sen realizes that people are motivated by non-self-interested motives, as well. In its place, Sen posits a capabilities approach which emphasizes a plurality of human rights, freedoms, and goals, instead of the poverty of utilitarian ethical monism.
Throughout the three lectures, Putnam carefully picks apart one of the most enduring shibboleths of modern philosophy. Like Rorty, with whom he shares many intellectual affinities, he has an explicit, self-conscious relationship with the analytic tradition. Unlike Rorty, however, he has not wholly eschewed that tradition. While he disagrees with many of its conclusions, he is able to use some of its assumptions and to break outside of the box of morally bankrupt positivism.
The last part of the book contains five essays of in tangential relation to the three main lectures. "On the Rationality of Preferences," one of the essays included in the collection, but not one of the three original lectures, is Putnam's answer to an interlocutor who made a curious criticism of the paper that he presented. Putnam's presentation considered a person who had two choices before them, A and B, neither of which the chooser preferred. Would it matter, he asks, if, instead of the chooser making the decision simply tosses a coin or gets a random person to make the decision for him? After all, they don't have a preference, right? Most classically trained economists would assert that it didn't matter who made the decision. In fact, that's what the interlocutor pointed out. However, this essay, Putnam's response, is a brilliant response defending the idea that, even though one might not prefer A to B, the ability to choose one's own option engenders a kind of "dignity of the self" which economists have heretofore ignored.