'Professor Putnam presents a powerful, coherent and persuasive system of thought. Ranging widely over the topics mentioned in their titles, the two volumes of essays yet have a remarkable degree of unity. Their themes overlap and are linked, as philosophical themes, seriously handled, must always overlap and be linked. In a period in which the general level of philosophical competence, as evidenced in publication, is extremely high, Putnam's work stands conspicuously out by virtue of its combination of technical sophistication, clear-sightedness, depth and power. Nothing of what he says is trivial, most of it is true and all parts of it are systematically interconnected. His prose - lucid, lively and unpretentious - is an excellent medium for his thought.' P. F. Strawson, The Times Literary Supplement