Preface
There is a saying that goes, 'Don't learn the tricks of the trade, learn the trade', but some 'tricks' are very important to philosophers. Thinking rationally involves the deployment of the right philosophical tool at the right time, be it Ockham's Razor, Hume's Fork or some other device from the thinker's toolbox. The most enduring contributions of the great philosophers are the thinking tools, methods and approaches they invent or discover, which often outlive the theories and systems they construct or those that they use their tools to dismantle. This book attempts to take the reader from the earliest examples forged by the ancients through to some of the 'state of the art' equipment employed by today's professional philosophers. The object is to show not merely what the great philosophers thought, but to demonstrate how they thought. Some philosophers, such as William of Ockham and Gilbert Ryle, bequeathed ideas with very specific applications while others such as Thales and Nietzsche are included here for their general approaches and methods. What follows is not an exhaustive inventory, and many great thinkers are left out. Spinoza and Leibniz, for example, are omitted not because their innovations were unimportant or have not lasted, but out of a concern to present that information which is most useful and readily digestible to the general reader.
Being able to apply the techniques of philosophy is a great aid to understanding the doctrines of its greatest exponents. One need not be a violinist to appreciate Vivaldi, but the way in which we metabolize knowledge is different from the way we enjoy music. As thinking human beings, we tend not to feel confident with knowledge learned by rote. Knowing how to multiply by seven, for example, is not just a question of memorizing the seven times table. Children are told that two sevens are fourteen, that three sevens are twenty-one and so on, but do not understand multiplication until they can calculate beyond the examples already given, i.e. 13×7, 200×7 … Real understanding requires participation on the part of the learner. We only truly know something when we have applied it, manipulated it or added to it, and this book is designed to enable the reader to do likewise. Moreover, in illuminating how philosophers thought, I hope that non-specialist readers will find themselves able to think along similar lines. It is characteristic of those with genius that their work be wholly original, yet at the same time eminently duplicable. Methods that took philosophical mastery to devise do not necessarily require a philosophical master to reproduce them. Though works of philosophy are sometimes mysterious or impenetrable, the tools used to create them are often remarkably simple and can be quickly grasped and brought to bear on the reader's own thoughts.
