Ben Dupre read classics a Exeter College, Oxford, Before pursuing a career in reference publishing. He has more than 20 years experience of elucidating difficult ideas for a popular audience. This book is from a series of “50 ------ Ideas You Really Need to Know.” This was a gift book.

His Introduction: “For most of its long history philosophy has had more than its share of dangerous people armed with dangerous ideas. On the strength of their supposedly subversive ideas, Descartes, Spinoza, Hume and Rousseau, to name but a few, were variously threatened with excommunication, obliged to postpone publication of their works, denied professional preferment, or forced into exile. And most notorious of all, the Athenian state regarded Socrates as so baneful an influence that they executed him. Not many of today’s philosophers are executed for their beliefs, which is a pity – to the extent, at least, that it is a measure of how much the sense of danger has ebbed away.

“Philosophy is now seen as the archetypical academic discipline, its practices firmly closeted in their ivory towers, detached from the problems of real life. The caricature is in many ways far from the truth. The questions of philosophy may be invariably profound and often difficult, but they also matter. Science, for instance, has the potential to fill the toyshop with all sorts of toys, from designer babies to GM foods, but unfortunately, it has not provided – and cannot provide – the instruction book. To decide what we should do, rather than what we can do, we must turn to philosophy. Sometimes philosophers get swept along by the sheer delight of hearing their own brains turning over (and it can indeed make entertaining listening), but more often they bring clarity and understanding to questions that we should all care about. It is precisely these questions that this book aims to pick out and explore.”

Each of the 50 ideas is covered in four pages – the first two have a timeline at their bottom and each has one or more sidebars and an interesting quote or two. The fourth page of each idea ends with “the condensed idea,” which I will include in parentheses after the title of the 4-pp subsection. The 50 ideas are grouped into nine sections. The number of subsections (i.e., the ideas) are in parentheses for each of the nine sections.

• 1. PROBLEMS OF KNOWLEDGE (1-6) – The brain in a vat (Are you an envatted brain?); Plato’s cave (Earthly knowledge is but shadow.); The veil of perception (What lies beyond the veil?); Cogito ergo sum (I am thinking, therefore I exist.); Reason and experience (How do we know?); The tripartite theory of knowledge (When do we really know?).
• 2. MIND MATTERS (7-11) – The mind-body problem (Mind boggles.); What is it like to be a bat? (Inside a bat’s mind?); The Turing test (Did you ever take that test yourself?); The ship of Theseus (What makes you you?); Other minds (Is there anybody there?).
• 3. ETHICS (12-24) – Hume’s Guillotine (The is-ought gap); One man’s meat ... (Is it all relative?); The divine command theory (Because God says so.); The boo/hoorah theory (Expressing moral judgments); Ends and means (The least bad option); The experience machine (Is happiness enough?); The categorical imperative (Duty at any cost); The golden rule (Do as you would be done by.); Acts and omissions (To do or not to do?); Slippery slopes (If you give them an inch …); Beyond the call of duty (Should we all be heroes?); Is it bad to be unlucky? (Does fortune favor the good?); Virtue ethics (What you are, not what you do).
• 4. ANIMAL RIGHTS (25-26) – Do animals feel pain? (Animal cruelty); Do animals have rights? (Human wrongs?).
• 5. LOGIC AND MEANING (27-32) – Forms of argument (Infallible reasoning?); The barber paradox (If it is, it isn’t – if it isn’t, it is.); The gambler’s fallacy (Against the odds); The sorites paradox (How many grains make a heap?); The king of France is bald (Language and logic); The beetle in the box (Language games).
• 6. SCIENCE (33-35) – Science and pseudoscience (Evidence falsifying hypotheses); Paradigm shifts (Science – evolution and revolution); Occam’s razor (Keep it simple.).
• 7. AESTHETICS (36-37) – What is art? (Aesthetic values); The intentional fallacy (Meanings in art).
• 8. RELIGION (38-43) – The argument from design (The divine watchmaker); The cosmological argument (The first and uncaused cause); The ontological argument (The greatest thing imaginable); The problem of evil (Why does God let bad things happen?); The freewill defence (Freedom to do wrong); Faith and reason (The leap of faith).
• 9. POLITICS, JUSTICE AND SOCIETY (44-50) – Positive and negative freedom (Divided liberties); The difference principle (Justice as fairness); Leviathan (The social contract); The prisoner’s dilemma (Playing the game); Theories of punishment (Does the punishment fit the crime?); Lifeboat Earth (Is there more room in the boat?); Just war (Fight the good fight).

In the 50 ideas listed above the parenthetical statement (meant to summarize the 4-page discussion of an idea) may leave you scratching your head as to how and why the idea (the title) led to Ben Dupre’s “condensed idea”. To see the connection between “the idea” of the title and the “condensed idea” requires reading and reflecting upon the brief 4-pp discussion. Although I was familiar with most, but not all, of these ideas, I greatly enjoyed the concise way he presented the discussion of each – many of which have not led to a consensus among philosophers. I was amazed that he was able to cover so much of the main ideas of philosophy in so few pages. He says little about the many philosophers who have discussed and argued (and are still arguing) over many of these ideas, but as for the 50 ideas summarized in the book, I think he chose well. I found this book to indeed be a valuable philosophy reference book and I highly recommend it to all, especially to those who have not been brave enough to read about the ideas of philosophy.