In Reasonable Hope considers three foundational responses to this quest for some understanding of the existence, meaning, and value of everything. Other approaches can be considered as combinations or variations of these. Firstly, there is the approach which claims that it is our humanity, exercising its unique intelligent subjectivity, that is the source and measure of all possible meaning and value. Nothing can be thought of as existing, meaningful or of value apart from a thinking human subject. This is a broadly Humanist approach to ultimate meaning. Man is the measure of all things. Secondly, there is the approach of Scientism. This claims that an ultimate understanding of the world and ourselves must be sought, less anthropocentrically, in terms of the findings of basic empirical sciences such as physics and chemistry. We live in a world ever-increasingly dominated by the autonomous system of science and technology. Such Scientism implies an explicitly reductionist and materialist conception of the meaning and value of everything. Thirdly, there is the approach of Theism which maintains that, in the final analysis, the meaning and value of everything, insofar as this can be known, is to be explained in terms of a transcendent infinitely perfect personal being we call God.
The first two approaches are carefully considered. However, it is the third to which most attention is devoted. Consideration is given to the traditional impersonal metaphysical approach to questions about the existence and nature of God. The alternative approaches of linguistic philosophy and phenomenology, which reject such metaphysical speculation are also discussed. These various approaches are judged to be complementary rather than strict alternatives.
In the latter half of the book is devoted to a more personal and self-involving discussion of the relevance of an affirmation of the existence of God. It explores the implications of a rational commitment to live one's life in accordance with the requirements of values which transcend explanation in purely physical terms, such as truth, goodness, beauty, and especially love. It provides a personal and existential development of the rational hope that such values are ultimately more objectively real and dependable than the eventual universal material chaos predicted by empirical science. It argues that the existence of God as the infinite expression and source of these values is the necessary and sufficient condition of this rational hope in their enduring significance. Finally, there is an account of how the Christian Revelation illuminates and transforms our rational hope in the enduring significance of love of God and neighbor.