Sidney, in his essay “An Apology for Poetry” gives poetry a place of honour above both philosophy and history and he says that poetry is the noblest medium of knowledge because it teacher us virtue and because it moves our minds to pursue virtuous action. There is no other branch of learning which can perform these two functions more effectively than poetry. Sidney asserts that there is no other knowledge more fruitful in this world than that which poetry supplies to the readers .It is the profoundest or the most fertile cause of knowledge or source of knowledge or repository of knowledge .He has compared poetry with other branches of knowledge.
He first claims the superiority of poetry as a medium of knowledge over moral philosophy .The philosopher is likely to say that it is he who really teaches human beings what virtue is, what the causes and effects of virtue are, and what vice or passion means. In other words, the philosopher claims to be a better teacher of virtue and virtuous conduct than anybody else. Here the historian is likely to step forward and challenge not only the claims of the poet but also of the philosopher .The historian will say that the philosopher teaches theoretical virtue while he teaches practical virtue. The philosopher teaches virtue by certain abstract considerations, while the historian teaches virtue by depicting in his history the experiences of mankind through the ages. But Sidney says, “The philosopher, therefore, and the historian are they which would win the goal, the one by precept, other by example”. But it is the poet who performs both the function of the philosopher and the function of the historian. The poet employs both precept and example .The abstract statements of the philosopher's are not easily understood by the reader, while the historian is tied to the particular truth of things and does not concern him with the general reasons of things. The example of the historians yields no general truth. The poet “coupleth the general notion with the particular example”.
Then Sidney has compared the poets’ way to the philosophers’ way in learning knowledge. The philosopher with his learned definitions of virtue and vices is unable to throw much light on the meaning of these terms. But the poet offers what may be called "speaking pictures" which convey the nature of virtue and vice most clearly .When a philosopher speaks of a man’s love of his country, he does so in an abstract manner which leave us cold. But when Homer depicts "old Achilles speaking in the midst of Troy’s flames” or Homer depicts "Ulysses in the fullness of all calypso's delights bewail his absence from barren and beggarly Ithaca," then we really understand what love of ones country means. If a philosopher tries to describe anger we would not understand it as clearly as when Sophocles depicts the "Ajax on a stage, killing and whipping sheep and oxen, thinking them the army of Greeks". Similarly when a poet depicts the "wisdom and temperance in Ulysses and Diomedes, volour in Achilles, friendship in Nisus and Euryalus, we understand these qualities much better than if a philosopher were to define and describe them. In short, the poet’s way is more effective in learning than a philosopher’s way.
Sidney says that poetry has the power to move the mind, which philosopher does not have. "And that moving is of a higher degree than teaching, it may by this appear, that it is well-nigh the cause and the effect of teaching”. It is poetry which can move the minds of the readers with a desire to learn Virtue. The philosopher shows the way to virtue but his way is tedious and even painful. People, following the path shown by the philosophers, are likely to get lost in the way. In this respect the poet is the monarch "for he doth not only show the way, but giveth so sweet a prospect into the way, as will entice any man to enter into it”. the poet "beginneth not with obscure definitions, which must blur the margent with interpretations, and load the memory with doubtfulness; but he cometh to you with words set in delightful proportion” and which are accompanied with music. A mere reading of poetry has often moved readers to become more courteous, more liberal, and more courageous. When we read the account of how Aeneas carried his old father Anchises on his back to safety we feel inspired to perform similar deeds of heroism.
Then Sidney has compared the poet to the historian and established the superiority of poetry over history. The historian, says Sidney, certainly deals with actual examples. But poetry is more philosophical and more studiously serious than history.
Poetry deals with the universal, while history deals with the particular. Such as poetry tells "what is fit to be said or done, either in likelihood or necessity” and history says “what Alcibiades did, or suffered”. History tells us what had actually happened while poetry tells us what should happen according to the law of probability or necessity.
The poet can ,in the portrayal of characters, depict the good qualities of human beings in such a way that we are prompted to follow their example and he can keep out the faults and the defects of those characters from our sight so that we may not be tempted to copy them.
The poet can, in his portrayal of Tantalus, Atreus Cyrus, Aeneas, keep out those Defects of these men which human beings should avoid. On the other hand historian can't hide their defects .The result of historian's portrayal is that the reader may be tempted to copy the defects of a man.
The historian is subject to the poet ;whatsoever action ,or fiction ,whatsoever counsel ,policy ,or war stratagem the historian is bound to recite "on the other hand that “may the poet with his imitation make his own ,beautifying it both for further teaching ,and more delighting"
"The historian, bound to tell things as things were, can not be liberal". A historian must portray alexander of scipio "some to be liked "some to be misliked". Thus it become difficult for the reader to decide which of the traits of this man should be granted and which should be avoided. On the other hand the poet can deviate from the actual facts or can violate it without being accused of untruth.
The historian must stick to the facts but the poet can beautify and alter the facts.
The Historian can't distribute punishments and rewards because he must not deviate from the actual historical happenings. On the other hand, the poet can show evil characters as being punished and good people being rewarded.
Sidney's grounds for ranking poetry as the greatest medium for knowledge above both philosophy and history are undoubtedly very sound. If we accept Sidney's premise that the final end of all learning is to bring about moral improvement in human beings, then we must also accept Sidney's view that poetry is the monarch of all forms of learning .We have to admit that poetry teaches virtue by delightful means. Poetry is thus better able to influence human conduct than philosophy or history and its influence is generally wholesome.