This book consists of several philosophical and scientific theories which define essential concepts, such as reality, science and justice. It presents a specific analysis of reality, according to which, reality is a set of potentialities, such as the potentiality of being abstract and the potentiality of being concrete, leading to the reconciliation between idealism and materialism. Also, in this book, justice is analyzed as the potentiality of maximizing freedom, equality and peace. The chapters of this book are interrelated in virtue of analyzing basic concepts in terms of potentialities.