In this account of Whitehead's thought I shall among other things be concerned with his mature philosophy as well as some of his earlier more mathematical and logical work. I believe that a study of Whitehead's pre-metaphysical writings can throw light on his later philosophy, and also show its relevance for modern thought. Too often Whitehead's views have been neglected because of his later reputation for obscurity in his metaphysical writings. Although few would wish to say that his major philosophical work Process and Reality is completely without philosophical significance, what this significance is, is not always clear to the cursory reader. Further, a good number of philosophers are put off by what looks like an attempt to inject "value" and "feeling" into physical nature.