In the preceding chapters reference has been made repeatedly to the order, laws or regularities which science seeks to discover among the phenomena of nature. A few explanations are now called for. When we speak of order or orderliness in nature, or in the world, what we mean, in the first instance, is the opposite of chaos or mere chance. In daily life we have frequent occasion to describe certain occurrences or concurrences as merely chance incidents or coincidences, while other occurrences are not treated as mere matters of chance. When dealing with human actions, the opposite of chance or accident consists of what is usually called design or purpose. Sometimes, for example, we meet friends by chance, at other times designedly, or of set purpose. But, when investigating the vast majority of natural phenomena, we are not concerned with problems of design or purpose. Here the opposite of chance is usually referred to as necessity, which must not, however, be taken to mean the same as compulsion, but simply conformity to a natural law or regularity of some kind. There are two questions then that have to be considered: (a) 99What is the attitude of science towards order in nature? and (b) what is meant by natural laws and regularities!