We may be good cooks or gourmets, and know how to cook and how to eat, but we should also know why we prepare a dish in a certain way and why this or that meat is particularly sapid. In fact, we must not forget that cooking is both an art and a succession of chemical reactions. That extra little knowledge will, besides, make the work more interesting and easier, the appreciation more acute, the criticism sounder. That is why an explanation of the great culinary principles ought to be useful to the readers of this book, and I shall deal with these in a manner as simple and as succinct as possible.