The History of Philosophy is a scientific and critical account of man’s effort to think out the ultimate and reasons of all things.
a. It is a scientific account: that is, it is a reliable history set forth in a manner that is systematic, orderly, and relatively complete.
b. It is a critical account: that is, it weighs and judges the doctrines which it discusses.
c. It is an account of man’s efforts to think out the ultimate causes and reasons of all things. The human mind has a quenchless thirst for knowledge. Man wants to know all that can be known about God, humanity and the world. Man wants to know everything about everything; he wants to understand all reality. Nor man is content with a list of facts or truths, but he also wants to know why the facts are so and how they come to be so. In other words, man wants to know facts together with their causes and reasons. Pushing this inquiry to its utmost limit, man comes to certain ideas and principles which he accepts as the roots and bases of all knowledge and of all reasoning. Beyond these fundamental things man finds that it is humanly impossible to inquire.
Upon these fundamental things man elaborates his interpretation of the universe – about God, humanity and the world. When man has done this, when he has pursued his quest of causes and reasons to the very end and has built up his interpretation of the universe, then he has achieved a philosophy. Philosophy is the science of all things knowable by the human mind and studied in and through their last causes and reasons, their ultimate “whats” and “whys” and “hows” and “wherefores”. Consequently, the History of Philosophy is the history of man’s inquiry into the ultimate causes and reasons of all things.
The importance of the study of the History of Philosophy is evident from the following descriptions of its character and function.
a. Philosophy is the highest human science because it traces out the ultimate causes and reasons of all things.
b. Philosophy is the fount from which all the separate or individual sciences draw their principles, criteria, and methods. In philosophy all the separate sciences find their ultimate unification, their place and interrelation in the entire scheme of human knowledge.
c. What men hold to be ultimately true about God, man and the world, has necessarily an enormous influence upon their conduct of life, their thoughts, volitions, and their action. In other words, philosophy exercises a large influence upon the activities of men, and this is true of men as individuals and as social groups.
d. It teaches us how the great mind of the past though through their doctrines.
e. If the history of man’s deeds is of interest and importance; if the story of human ideals and aspirations, dreams and fancies, is of recognized worth; then, surely, the first and highest value must attach to the history of man’s earnest and systematic thought, of man’s most far-reaching investigations of reality.
f. In its incidental discussion of false doctrines that have been proposed and defended in all ages, the history of philosophy affords the students the opportunity of profiting by the mistakes of others, and enables him to indicate for the benefit of those misled the illogical nature of erroneous doctrine. Thus it is both of practical and cultural importance.
g. It is the most interesting branch of study and it stimulates both the understanding and the memory.
The History of Philosophy may be developed according to the sequence of centuries or epochs (chronological method), or according to the major problems of philosophy, tracing each singly through its entire course of treatment by different philosophers in different ages (topical method).